Prepare Red Robin Pretzel Rolls according to the recipe linked to in the Box below.

Prepare Red Robin Beer Mustard according to the recipe linked to in the Box below. Set aside.

Place a large sauté pan over medium heat.

Add butter. Allow to melt and get hot, but do not burn.

When hot, add onion slices. Sauté until onions are tender and translucent. Remove from heat and spoon onions into a medium bowl.

Add 4 tablespoons Red Robin Beer Mustard. Mix. Add more mustard as needed, to taste. You want to make a nicely balance sandwich spread. Set aside.

Cook burger patties in any method you choose - grilled, stovetop, etc. Add 2 slices Swiss cheese to each burger during the last few minutes of cooking to melt.

Split Red Robin Pretzel Rolls.

Lightly toast insides of rolls on the grill, if using, on the stove top or in an oven set to broil.

Place bun bottoms onto a platter, serving plates or other work surface.

Place a lettuce leaf or helping of shredded lettuce on bun.

Place hot burger patty atop lettuce.

Spoon a generous helping of onion beer mustard over burger.

Add 3 slices Black Forrest ham to each.

Smear a bit of onion beer mustard on top bun and place over Black Forrest ham.

Serve immediately, hot.