Working in batches, melt ~1/2 tbsp butter in a skillet on medium heat and add buns, sliced side down to lightly toast. Remove from skillet when the sliced interior is golden brown and lightly toasted. Add more butter as needed as you toast the remainder of the buns.
Flatten ground chuck into round patties an inch larger than the size of the bun, as they will shrink when cooked. Salt and pepper each side and add to a separate skillet on medium high heat and cook until the top begins to turn a dark red, flip and top with cheese. Continue to cook until the burger is cooked through.
Warm bacon jam in microwave or in small saucepan.
Place slice of lettuce on bottom bun, topped with slices of onion, then add burger patty and top with two tablespoons of bacon jam and cover with the upper bun.
Recipe and photos courtesy of www.foxvalleyfoodie.com.