You know you have a good sandwich when you give it to six different people and they all eat it exactly as given. No one adds more of something or takes something off. Everyone just consumes it. That is a good sandwich.

Some of my favorite people gathered at my place for the Fourth of July to eat a bunch of food and play croquet before we went to the beach to enjoy some mildly dangerous fireworks. The centerpiece of the lunch was this sandwich, though if I have time this week I may do a few additional posts with more of the menu items because there were quite a few stellar things that I want to share.

This is a deceptively simple sandwich. It has very few components and so you might think that I have very little to tell you about putting it together but you would be wrong. I am going to overload you with details on those individual components because they include two of my very favorite things in all the land — grilled steak and caramelized onions.

Let’s start with the steak. You are going to want to make this steak on a charcoal grill. (Pause to admit horrible bias for charcoal grills and against gas grills and that is never changing because charcoal is just better.) You can do all sorts of things on a grill, but my favorite thing will forever remain taking a good quality steak and cooking it to a perfect medium rare. A simple thing and yet there are myriad ways to screw it up. After having grilled dozens and dozens of steaks, I have some very strong opinions on how to grill a steak.

Season simply and season early. Kosher salt and pepper is all that I ever use to season my steaks. Marinades and complicated spice rubs are for when you are working with tougher cuts. With a good tenderloin, you do not need all the bells and whistles. I place a rack (the kind that you would cool cookies on) over a baking sheet and lay my steaks out on it. I season them generously with kosher salt and fresh ground pepper on both sides and then place the sheet uncovered in the fridge for at least four hours, but overnight is preferable. The combination of the rack and the salt does double duty in drying out the exterior of the steak and drawing all the moisture towards the center, which helps you achieve that nice brown crust and luscious pink center.

Bring to room temperature before cooking. Remove your steaks for the fridge about an hour before cooking. Some people say fifteen minutes is plenty of time to get the steaks to room temperature. The truth is that it takes multiple hours but I usually have too much going on in the kitchen and find that one hour gets the job done well enough.

Go indirect heat or go really high heat. Indirect heat is terrific for cooking steak. You bank all your coals on one side and cook your steaks on the grill over the opposite side. This method of cooking steak requires a lot of attention. It takes a little longer due to the lower temperature and the cooler side of the grill will not have an even surface temperature so the edges of your steak nearer to the banked coals will be getting more heat. You have to flip the steaks multiple times to ensure that the cook and brown evenly but the steaks do cook more gently and so you have a thinner brown crust and more lovely pink meat. I cannot deny that it is worth the time for the perfectly cooked result. However, I often find it an impractical way of cooking since I usually have other things that I am grilling that require direct heat and switching from a direct to indirect setup is just a huge pain and not terribly effective. So, take a good look at your menu and decide whether you want to spend as much time hovering over the grill as you will need to for indirect cooking. For this specific occasion, I used high direct heat and it all worked fine. When cooking with high heat, you get a very even brown but you have to be very vigilant so you do not overcook the meat. I set a timer for three minutes and then flip and set a timer for three minutes again. (The steaks may require another minute or two, but with high heat, always err on the lower side of your cooking time when setting a timer.) Keep your thermometer handy and remove the steaks as soon as they hit 135 degrees. Not a moment longer. The high heat results in a thicker brown crust but you should still have a lovely piece of meat as long as you rest it properly. Speaking of which…

Rest is critical. In grilling as in life. What does resting the meat mean exactly? It means you let it sit there for fifteen minutes without cutting into it. This is so important. Many a steak has been ruined because someone took a knife and made a small slice to check to see if it was done. This is the worst way to check to see if a piece of meat is done. When a steak (or indeed any meat) is cooking, the juices are all drawn towards the exterior. The nice brown sear is keeping them contained. When the meat rests, the juices are reabsorbed into the meat. If you do not let a steak rest properly, juice will run everywhere when you cut it because the juice is still concentrated just at the surface. You lose all the juice that should be in the steak onto the cutting board. Also, the meat continues to cook as it rests. 135 degrees is not the final temperature of the steak you are eating. In fifteen minutes of rest, the internal temperature will go up another 10 degrees or so.

End of my brief steak tutorial and on to the onions.

Caramelized onions are another of my favorite things. They are also something that I do not make that often because they take a lot of time. You are looking at about 90 minutes from start to finish. You won’t be hovering over them. They are not labor intensive. However, I recognize that some people might think that it is too big a time commitment for what could be dismissed as a condiment. If you want to cut down the prep time for this sandwich, you could simply grill your onions. But I will think less of you. Know that.

My favorite recipe for caramelized onions is based on Deborah Madison’s recipe. I make two significant swaps. Her onions slow cook in white wine. I use vegetable stock. She finishes her onions with sherry vinegar. I use red wine vinegar. Neither of these are drastic changes. The end result is still the silkiest, brownest, tastiest caramelized onions I have ever had.

I served this sandwich on lightly toasted pretzel bread with mayo and stone ground mustard and some arugula. (The combination of ingredients came from Smitten Kitchen though I executed this basic idea in a completely different way. She grilled her onions. Let’s not talk about it.) Everything balances perfectly here. The bitterness of the arugula balances out the intense sweetness of the onions. Mayo and mustard provide nice base notes. You can use another bread (I am sure a toasted french roll would also be nice) though I quite liked the pretzel here.

Grilled Steak Sandwich with Caramelized Onions and Arugula
(adapted from Smitten Kitchen)

2 New York Strip Loin Steaks (about 10 oz each)
Kosher salt and pepper
1/2 cup caramelized onions (see recipe below)
2 handfuls arugula
6 pretzel rolls
Mayonnaise
Stone Ground Mustard

At least four hours (and up to twelve hours) before you will be grilling the steaks, season generously with kosher salt and pepper and place on a wire rack over a baking sheet. Place uncovered in the fridge. Remove the steaks from fridge one hour before you intend to grill them. (Leave them on the wire racks.)

Light your charcoal and bring it to high heat with coals evenly spread in the grill. Grill the steaks for three to five minutes on each side until an instant read thermometer reads 135 degrees. Let the steaks rest for fifteen minutes and then slice thinly.

Toast the bread on the grill. (Toasting bread on a hot grill takes seconds. If you put six pieces of bread on the grill, by the time you have placed the sixth piece, it is time to take the first one off.)

Spread mayo on the top side of the bun and mustard on the bottom. Lay the arugula and onions on the mayo bun and the steak on the mustard bun. Combine and devour.

NOTE: Since I was making this for a crowd, I used pretzel sausage rolls (buns designed for hot dogs rather than burgers) and halved them so everyone had a small sandwich and there were enough for folks to go back from seconds. On celebratory days, it is nice to be able to go back for seconds so I tried to portion things out to make that easier. The size was great and I would highly recommend it.

Caramelized Onions
(adapted from Deborah Madison)

2 tablespoons butter
3 lbs. white onions, sliced 1/4 inch thick
4 sprigs of thyme
1 1/4 teaspoons sea salt
1 cup vegetable stock
1 tablespoon red wine vinegar

Melt the butter over medium high heat and add the onions and thyme. Cook for about five minutes until the onions soften, stirring frequently. Add the salt and lower the heat. Cover and cook for twenty minutes. Add the stock and cover and cook for an hour, stirring every twenty minutes or so. When the onions are richly browned, turn off the heat and discard the thyme sprigs. (Most of the leaves will have come off the stems.) Stir in the vinegar. (Onions can be stored in the fridge for a few days but reheat over low heat on the stove before using.)