Steak Sandwiches

• servings: 4 servings
• total time: 30 minutes

Ingredients

1/3 cup mayonnaise

2 tablespoons smooth Dijon mustard

1 tablespoon whole-grain mustard

2 tablespoons sour cream (to make this dairy-free, just use additional mayo)

Kosher salt

1 (16-ounce) 1-inch thick New York strip boneless beef top loin or hangar steak

Kosher salt

Freshly ground black pepper

Olive oil, or a neutral high-heat oil such as grapeseed

2 medium-large yellow onions, sliced in thin rings

1/2 teaspoon fresh thyme leaves (if desired)

2 large or 4 medium (about 6″) focaccia or ciabatta buns, split and toasted, if you wish

1 cup baby arugula

Directions

Mix mayo, mustards, sour cream, and 1/8 teaspoon kosher salt in a small dish. Taste and adjust seasonings as needed. A shot of hot sauce is fantastic here.

Season the steak liberally with salt and pepper on both sides. Heat 1 tablespoon of oil in a large sauté pan over high heat until it’s almost smoking, then sear the steak on each side for 1 minute. Reduce the heat to low and cook the steak for about 7 to 10 minutes, turning once, until very rare in the middle. Remove to a plate and allow to sit for 10 minutes. Slice the steak into thin strips.

Using the same sauté pan, heat another glug of oil over medium heat. Add the onion, thyme, if you’re using it, salt, and pepper and sauté for 10 minutes, until the onions are brown and sweet, stirring occasionally.

To assemble the sandwiches, spread both sides of the split bun with the mustard-mayo mixture. Place a layer the steak strips on top of the mayo, sprinkle with salt and pepper, and top with the onions. Place the baby arugula on top of the onions, and cover the sandwiches with the top half of the buns.