Slice steak against the grain as thin as possible (maximum 1/8th inch thick).
In a large bowl, whisk together red wine vinegar, Worcestershire sauce, baking soda, 2 minced cloves of garlic, onion powder, dried thyme, salt, pepper, and 2 cups water.
Add sliced steak to the marinade mixture and set the timer for 15-30 minutes.
While the meat is marinating, slice the vegetables and grate the cheese.
Preheat oven to 400°F.
Heat 1 tablespoon of butter and 1 tablespoon of oil in a large skillet over medium heat. Drain the marinade from the meat and discard. Cook the meat in the hot skillet until cooked through. Batch cook the meat so that it isn’t overcrowded as it cooks. The baking soda from the marinade will result in some foaming in the skillet. This won’t affect the tenderness or flavor of the meat. Remove the meat from the skillet.
Add the remaining butter to the skillet. Saute the bell peppers and onions until softened, about 5 minutes. Add in remaining minced garlic and saute a minute longer.
Add the cream cheese and heavy cream to the skillet and cook until melted. Bring to a low simmer and stir in the grated cheese until melted. Remove from heat.
Put the steak back into the skillet, stirring to fully combine the mixture.
Spread into a casserole dish. Top with a layer of provolone cheese.
Bake for 15 minutes until the cheese has fully melted and toasted to a golden brown.
Sprinkle with chopped parsley and serve immediately.
Notes
Both flank steak or top sirloin will work for this recipe. Slice them very thin against the grain.
We recommend pepper jack cheese added to the cream cheese - it adds great flavor, but the dish is not spicy at all. Monterey jack or white cheddar can also be used.
Feel free to incorporate mushrooms, simply saute them with the bell peppers and onions.
We didn’t find that additional salt and pepper was needed, but you can certainly add a little salt and pepper to the meat while cooking.
Substitute garlic powder for the minced garlic, if you prefer.