Preheat oven to 205 °C (400 °F).
In a bowl, mix beef slices with half of the olive oil and the steak spice.
Spread meat on a baking sheet lined with parchment paper.
Add the green peppers, the Haiku shiitake mushrooms and the onion.
Drizzle the rest of the olive oil on the vegetables. Salt and pepper. Cook for 12 to 15 minutes.
Remove the baking sheet from the oven. Top the meat and vegetables with cheese, and continue cooking for another 3 to 4 minutes.
In a bowl, mix all ingredients for the sauce.
Slice the sub rolls lengthwise in half. Brush inside the rolls with sauce, and top with the meat/vegetable mix.
Fondue Beef Submarine
Prep time: 20 minutes
Cooking time: 15 minutes
Servings: 4 servings