Ingredients

• 1/2 c. full-fat Greek yogurt 
• 1/4 c. crumbled feta
• 2 tsp. freshly chopped mint
• 1 tsp. lemon juice
• Kosher salt
• Freshly ground black pepper
• 1 lb. ground lamb
• 4 hamburger buns
• 1/4  red onion, thinly sliced into rounds
• Arugula, for serving

Instructions

1. Step 1In a medium bowl, stir to combine yogurt, feta, mint, and lemon juice. Season with salt and pepper.
2. Step 2Divide ground lamb into 4 equally sized patties. Make an indent with your thumb in the center of each patty, and season both sides generously with salt and pepper.
3. Step 3Heat a large cast iron skillet over medium-high heat. Add burgers and cook  until crisp on the outside and still slightly pink in the center, 3 to 4 minutes per side for medium.
4. Step 4Spread each top and bottom bun with yogurt sauce. Top with the patty, red onion, arugula, and top bun.