Begin by washing and chopping the potatoes, bell peppers, and onions into small, uniform pieces for even cooking. Aim for bite-sized chunks to ensure a delightful texture in your Italian hot dogs.

In a large skillet, heat a couple of tablespoons of olive oil over medium heat until shimmering, about 2 minutes. Add the diced potatoes to the pan, seasoning them with a pinch of salt. Cook for approximately 20 minutes, stirring occasionally, until they begin to brown.

Once the potatoes are crispy, stir in the chopped onion and bell peppers. Sauté for an additional 8-10 minutes, stirring frequently until onions become translucent and peppers soften.

Sprinkle in Italian seasoning and optional crushed red pepper to your sautéed veggie mix. Stir thoroughly so the spices coat the vegetables evenly.

Push the vegetable mixture to one side of the skillet and add the hot dogs directly to the other side. Cook them for about 5-7 minutes, turning occasionally, until browned and heated through.

Remove the pan from heat and assemble the hot dogs. Place the cooked hot dogs into hoagie rolls, topping them generously with the potato, onion, and pepper mixture. Top with a drizzle of stone-ground mustard.