1. In a large bowl, mix ground turkey with Dijon mustard, Worcestershire sauce, garlic powder, onion powder, thyme, salt, and pepper. Do not overmix. Shape into 4 patties.

2. Heat 1 tablespoon of olive oil in a skillet over medium-low. Add sliced onions and cook for 20-25 minutes, stirring occasionally, until caramelized. Add balsamic vinegar and cook 2-3 more minutes. Set aside.

3. Heat remaining olive oil in a grill pan or skillet over medium heat. Cook patties for 5-6 minutes per side or until they reach 165°F. Add provolone slices during the last minute to melt.

4. Toast brioche buns lightly. Layer bottom bun with balsamic onions, add the patty, top with arugula or spinach, and place the top bun. Serve immediately.

5. Store leftover patties in the fridge (up to 3 days) or freezer (up to 2 months). Reheat in skillet or oven.