Over a grill, toast the inside layer of hoagie rolls and set aside.
TIP: If you’re camping or bringing this dish for a bbq potluck or hang, try making the pepper/onion mixture in advance to save yourself time. We also recommend slightly toasting your hoagie by placing it face down on the grill’s surface. This will make it extra crunchy but also provide an extra barrier to protect the rest of the bread against the wet filling and soft cheese.
In a large cast iron pan, melt butter over medium heat and cook down garlic, onions, bell peppers and jalapenos for 45 minutes or until the onions become translucent, fragrant, and sweet- stirring regularly.
Remove from heat, stir in both red wine vinegar and chopped parsley, and set aside (this step can be done up to one day ahead of time and reheated in a pan later).
Heat oil over medium-high heat in another cast iron skillet, and as the oil comes to temperature, season your steak with cajun seasoning, salt, and pepper.
Cook steak strips in oil until the outer layer appears seared (about 7 minutes) and the meat has cooked through, and set aside.
Return to your toasted hoagie rolls and layer onion mixture, steak strips (still hot), and triangled Swiss cheese onto the hoagie, melting the cheese. Serve hot.
