Melt butter in a large pot over medium heat. Add onion and bell pepper; saute until soft, 5 to 7 minutes. Add ground beef, garlic, salt, and 1 teaspoon pepper. Cook and stir until beef is browned and crumbly, 7 to 8 minutes. Drain and discard grease.

Add broth, steak sauce, Worcestershire sauce, jalapeno peppers and juice, and 1/2 teaspoon Creole seasoning; stir to combine, then bring to a boil. Reduce heat and simmer for 5 minutes.

Meanwhile, mix cornstarch and water together in a small bowl.

Add cornstarch slurry to beef mixture and cook to desired consistency, 1 to 2 minutes. Taste and add additional Creole seasoning and pepper if needed. Turn off heat.

Melt 1 slice of provolone cheese on top of the meat. Scoop the meat from under the provolone and place on a toasted bun. Repeat with remaining cheese and buns and serve immediately.