Before starting, preheat the oven to 450°F. Wash and dry all produce. Heat Guide for Step 6 (dbl for 4 ppl): 1/2 tsp mild, 1 tsp medium, 1 1/2 tsp spicy and 2 tsp extra-spicy! Cut sweet potatoes into 1/2-inch thick wedges. Add sweet potatoes, 1 tbsp oil and 1 tsp Montreal Steak Spice to a parchment-lined baking sheet, then toss to combine. (NOTE: For 4 ppl, use 2 parchment-lined baking sheets, with 1 tbsp oil and 1 tsp Montreal Steak Spice per sheet.) Roast in the middle of the oven, flipping halfway through, until golden-brown, 22-24 min. (NOTE: For 4 ppl, roast in the middle and the top of the oven, rotating sheets halfway through.)

Peel, then mince or grate garlic. Core, then cut pepper into 1/4-inch slices. Peel, then cut onion into 1/4-inch slices. Remove the stems from portobellos, then scrape off the dark brown gills on the underside and discard. Cut portobellos into 1/4-inch slices.

Heat a large non-stick pan over medium-high heat. When hot, add 1 tbsp oil and 1 tbsp butter (dbl both for 4 ppl) and swirl pan until butter melts. Add garlic, onions, portobellos , peppers and remaining Montreal Steak Spice. Season with salt. Cook, stirring often, until softened, 8-10 min.

Sprinkle mozzarella evenly over the veggies. Turn off heat and leaving the pan on the stovetop until cheese melts.

While the veggies cook, halve rolls. Add rolls directly to the top rack of the oven, cut-sides up. Toast, until golden, 2-3 min. (TIP: Keep your eye on them so they don't burn!)

Stir together half the mayo and 1 tsp sriracha in a small bowl. (NOTE: Reference Heat Guide.) Spread remaining mayo on the rolls, then divide the veggie filling between each roll. Divide hoagies between plates with pickles and sweet potato wedges alongside. Serve spicy mayo on the side, for dipping.