I tried another recipe recently, with chopped up onion and bouillon instead of the lipton soup mix. I didn't like them nearly as well - the recipe below is our favorite so far.
1 1/2 lbs ground chuck
1 (4 tablespoon) envelope onion soup mix
1/2 teaspoon pepper
2 tablespoons water
1/3 cup breadcrumbs
24 small square dinner rolls (Hawaiin Rolls are great!)
Cheese (optional. American is traditional, but I will not use "American" cheese, we usually use Muenster. Sometimes provolone.)
1/2 cup mustard
1/2 cup ketchup
Preheat oven to 400°F. Mix first 6 ingredients and press into an ungreased 10 by 15 inch pan. (I use my Pampered Chef bar pan) Prick with a fork. Bake for 10 minutes.
Drain off juices (if there's a lot of excess).
Cut into 24 squares. Place squares on dinner rolls. (I use hawaiin rolls, because I can get them at Sam's club, and that is about the only place I shop.
Combine mustard and ketchup and spread on rolls. Top with pickles and cheese, if desired.
Makes 24 sliders.