Sous Vide Lamb Burgers with Mint and Sweet Chili Sauce

Ingredients

• 1 slice white sandwich bread, torn into 1/2-inch pieces
• 1/4 cup whole milk
• 1 pound ground lamb
• 1 pound ground beef
• 2 cloves garlic, minced, divided
• 3 tablespoons finely minced onion
• 1/4 cup plus 3 tablespoons sweet Thai chili sauce
• 1/4 cup chopped fresh mint leaves, plus more for garnish
• Salt and freshly ground black pepper
• 1 English cucumber, sliced into 1/4-inch-thick rounds
• 1/2 cup plain Greek yogurt
• 1 medium tomato, diced
• Juice of 1 lemon
• 1/2 teaspoon ground cumin
• 1 tablespoon extra virgin olive oil
• Chopped lettuce, for serving