Rach's Burger of the Month: Turkey Cheeseburgers with Bacon & Apple-Onion Relish

Name: Rach's Burger of the Month: Turkey Cheeseburgers with Bacon & Apple-Onion Relish
Cuisine: American
Ingredients: 2 tbsp. butter; 2 onions, chopped; 1 bay leaf; Salt and finely ground black pepper; 2 Honeycrisp or Gala apples, peeled and chopped; ¼ cup pure maple syrup; 2 tbsp. fresh thyme leaves, finely chopped; ⅛ tsp. freshly grated nutmeg; ½ cup grainy Dijon mustard; 12 slices meaty smoked bacon; 1 ½ lb. ground turkey, a blend of dark and light meat; 2 tbsp. Worcestershire sauce; 1 tsp. each coarsely ground black pepper, ground white pepper, and granulated garlic; 1 tbsp. vegetable or olive oil; 8 oz. sharp white cheddar, sliced or crumbled; 4 brioche buns or other burger buns, lightly toasted; Sliced bread-and-butter pickles or dill pickles