COOK IT.
Preheat your wood pellet grill to 350°F.
Coat the steak with your oil of choice and season with salt and pepper.
Open your grill's sear plate and grill steak to desired temperature over direct flame. Baste with chimichurri sauce on both sides during this process.
Close the sear plate and place whole the loaf of bread on the upper rack. Close the grill lid to warm the bread and make the outside slightly crispy.
Allow the steak to rest for 10-15 minutes.
Remove the bread from the grill and slice in half, lengthwise.
Spread aioli on top and bottom half of the bread.
Slice the steak thinly and evenly and place on the bottom half of your loaf.
Top the steak with charred peppers, shaved onions, grilled mushrooms, and fresh arugula.
Top with remaining half of bread and cut into 4-6 equal-sized portions.