Bison Burger with Caramelized Onions (Crowd Cow)

Ingredients

• 2 onions, thinly sliced
• 3 Tbsp butter
• Pinch of salt
• 1 lb Ground Bison
• 1/2 Tbsp Worcestershire sauce
• 1 tsp onion powder
• 1 tsp thyme
• 1 tsp garlic, minced
• 1/2 tsp salt
• 1/2 tsp pepper
• 4 slices white cheddar cheese
• 4 hamburger buns
• Lettuce
• tomato