Vegan Fajitas with Creamy Cilantro Sauce

Preheat the oven to 400ºF. On a large rimmed sheet pan, add the sliced portobello mushrooms, bell peppers, and onion, and toss well with the olive oil.
In a small bowl, mix the chili powder, garlic powder, cumin, smoked paprika, and salt. Sprinkle it evenly over the veggies and toss well. Place the pan in the oven and roast until the veggies are tender, about 25 minutes. There's no need to stir; the veggies will shrink as they cook.
While the vegetables cook, prepare the cilantro sauce. Add the cilantro, lime juice, hemp hearts, water, garlic, red pepper flakes, and salt to a blender. Secure the lid and blend until smooth. Taste the mixture and add an extra ¼ teaspoon of salt or red pepper flakes to boost the flavor, if needed. Set the sauce aside until ready to serve.
Warm the tortillas by placing them in a dry skillet over medium-high heat for 30 seconds, then flip and warm the other side. Repeat with the remaining taco shells. Alternatively, you can wrap the stack in foil and place them in the oven for the last 10 to 15 minutes of the vegetable cooking cycle.
When the veggies are done cooking, serve them warm in the tortillas with the cilantro sauce and any other toppings you like. Make them more filling by adding refried beans or bean dip to each tortilla. Leftovers can be stored in separate airtight containers for up to 5 days.