Lamb Burgers with Tzatziki and Arugula

Ingredients

For the tzatziki:

• 1 1/2 cup sheep's milk yogurt (or whole milk yogurt)
• 1 small kirby cucumber
• 2 finely chopped garlic scapes
• 1 tablespoon chopped mint

For the burgers:

• 2 pounds ground lamb or mutton
• 6 English muffins
• 2 cups baby arugula
• Salt and freshly ground black pepper

Method 

1. Place the yogurt in a cheesecloth-lined strainer or colander, set over a bowl, and strain for 4 hours in the refrigerator to thicken the yogurt.
2. Finely dice the cucumber, transfer to a colander, and season with 1/2 teaspoon of salt. Let drain for one hour. Transfer to a bowl and add the yogurt, garlic scapes, mint, and lime zest and juice. Season with salt and pepper.
3. Prepare the burgers: Divide the lamb into six 1-inch patties. Heat a grill pan or cast-iron skillet over medium-high heat, and add 2 to 3 patties to the dry pan. Do not crowd the pan. Cook for 3 to 4 minutes per side for medium-rare. Remove from heat and let rest for five minutes. Repeat with remaining patties. Serve on toasted buns with tzatziki and a handful of baby arugula.