Wash and dry all produce. Core and seed poblano, then thinly slice crosswise. Halve, peel, and thinly slice onion. Finely dice a few slices until you have 3 TBSP diced onion and set aside for garnish. Drain pineapple. Cut lime into wedges. Pick cilantro leaves from stems; discard stems.

Heat a drizzle of oil in a large pan over medium-high heat. Add poblano and sliced onion. Cook, tossing, until lightly charred, 5-6 minutes. Remove from pan and set aside.

Heat another drizzle of oil in same pan over medium-high heat. Add pineapple to pan and cook, tossing, until lightly browned, 2-3 minutes.

Add seitan to pan. Cook, tossing, until lightly browned, 2-3 minutes. Stir in Southwest spice blend and chipotle powder (to taste—start with a pinch and go up from there). Cook until fragrant, about 1 minute.

Meanwhile, wrap tortillas in a damp paper towel and microwave on high until warm, about 30 seconds. TIP: Alternatively, wrap tortillas in foil and warm in oven for 5 minutes at 400 degrees.

Spread a bit of sour cream on each tortilla, then top with seitan, veggies, diced onion, and cilantro. Serve with lime wedges on the side for squeezing over.