Just made these the other night, they were a huge hit :) This recipe comes from Deep South Dish :)
Roast Beef, Caramelized Onions and Horseradish Sliders
3 to 4 pound beef chuck roast (or other braising roast)
1 cup of water
One envelope of dry onion soup mix
One envelope of dry Italian dressing mix
One envelope of dry brown gravy mix
1 (8 ounce) jar of Pace Original Mild Picante Sauce
Whisk together the water with ingredients from all 3 of the envelopes. Pour about 1/4 cup of the liquid on the bottom of the crockpot, place the roast on top. Don’t be tempted to season the roast. There is plenty of salt and other seasonings in these envelopes.
Pour the remaining liquid mixture all over the top and all around the roast. Pour the jar of picante sauce on top of the roast, cover and cook on low for 8 hours, or on high 4 to 5 hours.
Preheat oven to 400 degrees F. Butter the insides of dinner rolls and toast, butter side down, on a baking sheet in the oven just until warmed through and browned on the bottoms. Meanwhile in a skillet, caramelize a sliced onion in a tablespoon of canola oil and one tablespoon of butter. (I omitted both and just used my non stick pan, I didn’t want the extra fat)
Use a fork to shred the meat. Place a scoop of beef on the bottom half of dinner rolls, then top with caramelized onion, and some finely shredded Swiss cheese.
All I did after this step, was to add a little horseradish sauce and then put the tops back on and popped the sliders into the oven just to melt the cheese.