Preheat the Griddle: Set your Blackstone griddle to low heat with the two inside burners on and the outside burners off.
Cook the Veggies: Add the diced onion and sliced bell peppers to the griddle. Let them cook for about 5 minutes, stirring occasionally.
Toast the Buns: Once the veggies are softened, place the buns on the griddle to toast. You can toast yours to your preference, or you can steam them for a softer texture.
Cook the Beef: Add the pre-shaved beef to the griddle, spreading it out so it doesn't overlap. Let it cook for about 1 minute before dividing it into two piles. Add the cooked peppers and onions to the beef piles.
Season & Chop: Sprinkle the beef with salt to taste. Chop up the beef and veggies with two spatulas, mixing everything together.
Add Cheese: Create four even piles of the beef mixture (bun-length). Place 2 slices of provolone cheese on top of each pile. Tent the buns over the cheese to help it melt, adding a little water to help with the steaming process.
Finish & Serve: Once the cheese has melted, lift the buns off and check the cheese— it should be perfectly melted and bubbly. Carefully flip each pile with the spatula, forming your cheese steak sandwiches. For extra flavor, add sliced jalapeños on top.
Serve: Serve your cheese steaks with a side of Salt and Vinegar chips, and enjoy your backyard sandwich feast!