Ingredients

½ cup mayonnaise

½ cup sour cream

2 tsp Worcestershire sauce

2 tsp Dijon mustard

1 tsp paprika

1 clove garlic, minced

Salt

Pepper

1 lb 85% lean ground beef

1 Tbsp oil

3 Tbsp butter, divided

8 oz cremini mushrooms, sliced

1 yellow onion, sliced

4 Kaiser rolls

Several leaves of lettuce, for serving

Instructions

Step 1: In a medium bowl, mix together mayonnaise, sour cream, Worcestershire sauce, Dijon mustard, paprika, and minced garlic. Season lightly with salt and pepper. Set this sauce aside.

Step 2: In a large bowl, season the ground beef with 1 teaspoon salt and ¼ teaspoon pepper. Mix gently to combine, taking care not to overwork the meat.

Step 3: Divide the beef into 4 equal portions. Shape each portion into a tight ball, then flatten into a disc. Pinch the center to make it slightly thinner than the edges. Set aside.

Step 4: Heat oil and 1 tablespoon butter in a medium skillet over medium heat. Add sliced mushrooms and onions. Cook, stirring occasionally, until softened, about 5–8 minutes. Season lightly with salt and pepper, then remove from heat but leave them in the skillet.

Step 5: Heat a large skillet over medium heat. Add the burger patties and cook until deeply seared on the first side, about 3–4 minutes. Flip and cook on the second side until the internal temperature reaches 160°F, about 4–6 minutes more.

Step 6: Transfer the cooked burgers to a plate and let them rest briefly.

Step 7: Return the skillet with mushrooms and onions to low heat to warm through.

Step 8: Slice the Kaiser rolls in half. Melt the remaining 2 tablespoons of butter in the skillet over medium heat. Toast the buns cut-side down for about 1 minute until golden, then remove from the pan.

Step 9: To assemble, spread the mayonnaise mixture on both cut sides of each bun. Place lettuce leaves on the bottom bun, followed by a burger patty, then a generous helping of the mushroom and onion mixture. Top with the other half of the bun and serve immediately.

Tips & Variations

For a creamier sauce, add a touch of sour cream on top of the assembled burger before serving.

Swap cremini mushrooms for button or shiitake mushrooms for a different texture and flavor.

If you prefer a spicier kick, add a pinch of cayenne pepper to the mayo sauce mixture.

Use brioche buns instead of Kaiser rolls for a slightly sweeter sandwich.

FAQs

Can I use a different type of ground meat?

Yes, you can substitute ground turkey or chicken, but cooking times may be shorter and the flavor will be milder. Adjust seasoning accordingly.

How do I know when the burger is fully cooked?

Use a meat thermometer to check that the internal temperature reaches 160°F (71°C) for a safe, fully cooked burger. This ensures it’s juicy and tasty without undercooking.