Smashed Burger

680 g beef mince
½ cup Best Foods Mayonnaise
1 tbsp American mustard
1 tbsp grated yellow onion
2 tsp SIDS RINGS AROUND URANUS SAUCE
4 white hamburger buns or BAPS
2 tbsp butter, room temperature
2 tsp SIDS SALT & PEPPER
4 slices Cheese & Chives
2 cups torn Iceberg lettuce
8 slices tomatoes

Divide ground beef into 8 equal balls about the size of a ping-pong ball then refrigerate.
In a small mixing bowl, whisk together mayonnaise, mustard, grated onion, SIDS RINGS AROUND URANUS SAUCE to create a special sauce; refrigerate.
Using either a large cast iron griddle or 2 large cast iron pans heated to high, toast buns with butter then reserve to plates.
Space beef balls on hot cooking surface. Using a large metal spatula, smash each ball to 6 mm-thick patties. (Tips: using the handle of a second spatula to push down on the top of the spatula adds leverage. Using baking paper helps avoid spatula sticking to beef)
Season patties with a of reserved special sauce per patty and SIDS SALT & PEPPER. Sear 2-3 minutes until some fat begins to bubble up in centre of patty. Quickly flip and top 4 of the patties with a slice of cheese. Sear another minute and place a plain patty atop a cheese patty then remove from cooking surface.
Build burgers with a smear of special sauce on bottom bun followed by shredded lettuce, tomato, double burgers and top bun.