Ham & Swiss Marinated Buns

Marinade:
1 cup (2 sticks) butter
2 Tbsp poppy seeds
1 Tbsp Worcestershire sauce
2 Tbsp hot, spicy or Dijon mustard
1/4 cup brown sugar
Sandwiches:
24 (about 2 x 2-Inches each) small dinner rolls (see Note)
Horseradish mayonnaise (see Note)
24 (about 3/4 pound) thin slices of deli ham (see Note)
24 (about 1/2 pound) thin slices of Swiss cheese
Line two 9 x 13-inch baking pans with non-stick foil or butter traditional pans.
Regular Recipe: To prepare marinade, melt butter over low heat. Add Worcestershire Sauce, Brown Sugar and Mustard. Stir until Brown Sugar is melted into the sauce. Remove from heat and let cool.
Optional: Start preparing the marinade by sauteeing 1/4 cup minced sweet onion in butter over low heat until onion is soft and translucent. Then proceed with the rest of the marinade as listed above. When done mixing the marinade and removing from the heat, mix in 1tbsp parsley
Slice the buns in half. Spread bottoms of buns with a thin layer of Horseradish Mayonnaise. Fold ham slices to fit the bottom of each bun. Repeat with Swiss cheese slices, folding to fit buns. Replace bun tops. Place ham and cheese buns into prepared baking pans. Pour marinade evenly over both pans of buns. Cover tightly with foil. Refrigerate overnight.
Preheat oven to 350 F. Bake marinaded buns covered for 25 minutes. Remove foil and bake an additional 10 minutes.
Notes: Use pre-baked dinner rolls. If you make your own yeast dinner rolls, all the better. If you're on a budget, adjust this method to use large yeast hot dog rolls, cut into thirds (you may need to adjust the baking time). Horseradish mayonnaise is easy to make at home, but there are decent commercial varieties to use as a shortcut. You can use regular mayonnaise if you need to avoid horse radish. For the ham, I used a rosemary sun-dried tomato deli ham, but feel free to use your favorite. Just be sure it is sliced very thin and use a high-grade, low-moisture ham for best results.
Serve these warm, right from the oven for best results

Also, when the guy from work made these, he used WHEAT dinner rolls.
