Steak sandwich with cheese sauce and onion rings

Ingredients:

Beef

• 1 strip steak weighing 170 g.
• 1 teaspoon garlic powder
• 1 teaspoon of salt

Onion rings

• Rapeseed oil (canola), for frying
• 2 large onions, cut into 2cm thick rings.
• 2 cups of sour milk or kefir
• 2 cups of flour
• 1 teaspoon of salt
• A pinch of cayenne pepper

Mustard and cheese sauce

• 110 g butter
• 0.5 cups flour
• 1 liter of chilled whole milk
• 350 gr. fontina cheese, grated
• 2 drops Tabasco sauce
• 1.5 tbsp Dijon mustard
• 1.5 tbsp. grainy mustard

Innings

• 1 long sesame seed bun
• 220 g thin slices of fontina cheese
• Thinly sliced ​​canned banana peppers
• A handful of arugula

Preparation:

1. Steak:
   
   Preheat a grill pan over medium-high heat. Sprinkle both sides of the steak with garlic powder and salt. Place on the grill pan and cook for 5-7 minutes, flip and cook for another 3-5 minutes until medium rare. Transfer the steak to a cutting board and let it rest. Slice the steak diagonally.
2. Onion rings:
   
   Attach a deep-fry thermometer to a heavy-bottomed saucepan and add 2–3 inches of vegetable oil. Heat the oil to 350°F (180°C). Meanwhile, pour the buttermilk into one bowl and combine the flour, salt, and cayenne pepper in a second bowl. Dip the onion rings, a few at a time, in the buttermilk, then coat them in flour; repeat. Carefully lower the breaded rings into the hot oil, being careful not to overcrowd the pan. Once the onions are golden brown on one side, flip them over and fry until golden brown on all sides. Transfer them with a slotted spoon to a plate lined with paper towels. Season with salt to taste.
3. Mustard and cheese sauce:
   
   Melt the butter in a medium saucepan. Add the flour and stir to form a roux. Stirring constantly, gradually add the cold milk until fully incorporated and the sauce begins to thicken. Add the fontina, Tabasco, Dijon, and grainy mustard. Season with salt and remove from heat.
4. Sandwich:
   
   Spread cheese sauce on each slice of bread, top with sliced ​​fontina, banana peppers, steak, and arugula. Serve with onion rings.