Wash and dry all produce. Halve, peel, and thinly slice onion. Mince a few slices until you have 3 TBSP minced onion. Core and seed poblano, then thinly slice. Core and seed tomato, then dice into 1/4-inch cubes. Peel kiwis, then dice into 1/4-inch cubes. Finely chop cilantro. Zest lime until you have a big pinch of zest, then cut into wedges.

Combine tomato, minced onion, kiwis, a squeeze of lime juice, and half the cilantro in a small bowl. Season with salt, pepper and more lime juice (to taste). Set aside.

Heat a large drizzle of oil in a large pan over medium-high heat. Add poblano and sliced onion. Season with salt and pepper. Cook, tossing, until softened and slightly charred, 3-5 minutes.

Add seitan and another drizzle of oil to pan and toss to combine. Season with salt and pepper. Cook until seitan is warmed through and starting to brown, about 5 minutes. Reduce heat to low to keep warm, stirring occasionally.

In another small bowl, combine lime zest, a squeeze of lime juice, and sour cream. Season with salt, pepper, and more lime juice (to taste).

Wrap tortillas in a damp paper towel and microwave on high until warm, about 30 seconds. Fill tortillas with seitan mixture, then top with kiwi salsa and dollop with lime crema. Sprinkle with remaining cilantro. Serve with any remaining lime wedges on the side for squeezing over.