Butter Burgers

10 tbsp butter softened
1 onion chopped
1 tbsp SIDS LOW SUGAR RASPBERRY VINEGAR
1½ tsp SIDS SALT & PEPPER
500 g ground beef
SIDS HOT WORCESTER SAUCE
4 fresh hamburger buns, lightly toasted
1 tsp rice bran oil
4 slices Tasty cheese

In a large frypan, melt 2 tablespoons butter over medium heat. Add chopped onion, SIDS LOW SUGAR RASPBERRY VINEGAR and ½ teaspoon SIDS SALT & PEPPER. Cover and cook, until tender, about 5 minutes. Reduce heat to medium-low and remove lid. Continue to cook until onions are translucent and just beginning to brown, about 3 more minutes. Transfer onions to a plate and divide into 4 equal portions then set onions aside until ready to use.
Divide beef into 4 equal sized portions and gently shape each into a 100x12 mm patty. Brush both sides of the patties with SIDS HOT WORCESTER SAUCE and SIDS SALT & PEPPER. Refrigerate the patties 15-30 minutes.
Spread each bun top with 2 tablespoons butter then set aside.
Heat oil in the same frypan used for the onions until the oil just begins to smoke. Use a spatula to transfer the patties to the frypan and cook 3 minutes. (without moving them) Flip the patties and cook 1 more minute. Place 1 cheese slice over each patty and continue to cook until cheese is melted, about 20-30 seconds more.
Transfer patties to the bun bottoms and place ¼ of the sautéed onions on each patty. Top each with the buttered bun tops and serve immediately.