Pot Roast Sandwiches!

Cut roast into large cubes. Add the cubed roast, sliced yellow onion, onion soup mix seasoning packet, ranch seasoning, cajun seasoning, garlic powder, garlic & herb seasoning, unsalted butter, pickled hot jalapeños peppers, a splash of jalapeño juice, and 1 cup water to a crockpot. Cook on high for 6 hours. Remove the roast and shred it with 2 forks. In a separate bowl, prepare a cornstarch slurry by mixing 2 tbsp cornstarch with 1/2 cup cold water. Add the cornstarch slurry to the crockpot and mix it in. Return the shredded roast to the crockpot and keep it on warm. Serve on sandwiches, optionally with swiss cheese.