In the crockpot, throw in the onion, 1 tsp brown sugar and 1 tbsp Worcestershire sauce. Add 2 tbsps of butter and the steak. Sprinkle the onion powder and 1/2 tsp salt on top. Place the chopped red pepper around the steak and then pour in the 2 cups of chicken broth and 1 tablespoon of soy sauce. Cover and cook on high for 4-5 hours, or on low for 6-8 hours.
Once the steak is tender, tear and shred the meat with a knife and fork (I did this with the meat still in the crockpot. Stir in the the chopped parsley.
Preheat the oven to 425 degrees F. On a sheet pan lined with foil, place the carrots and broccolini and drizzle with a bit of oil. Sprinkle red pepper flakes onto the carrots. Roast in the oven for about 20 minutes, or until the broccolini is crisp and the carrots are soft. Let the veggies cool for a few minutes
In a food processor or blender, transfer the carrots and add 1/4 cup of mayonnaise, 5 tbsp of olive oil and 2 tsp of the white vinegar. Pulse until smooth or only small chunks remain.
Bring the oven's temperature down to 400 degrees. Spread some of the carrot mayo onto each hot dug bun, followed with a slice of cheese and a few spoonfuls of the steak and pepper mixture. Top with a few pieces of broccolini. Wrap each sandwich in foil and place them sitting upright on a baking sheet. Bake in the oven for 5-7 minutes, until the buns are toasted and the cheese is melted.
Enjoy with fries or pickles if desired!