Prepare the Chipotle Pecan Pesto by blending roasted pecans, chipotle peppers in adobo, garlic, and a drizzle of olive oil in a food processor until smooth.

Heat 1 tablespoon of avocado or olive oil in a large skillet over medium heat, add sliced red onion, and sauté for about 3-4 minutes until golden brown.

Add sliced bell pepper and cook for another 4-5 minutes until tender and slightly caramelized, then remove the vegetables from the skillet.

In the same skillet, add another tablespoon of oil and medium-high heat, then add sliced Portobello mushrooms and sauté for 2-4 minutes on each side until browned and tender.

Return the sautéed onions and peppers to the skillet, sprinkle in oregano, garlic powder, and sea salt, stir and cook for an additional 2-3 minutes until heated through.

Warm the canned refried beans in a separate saucepan over low to medium heat for about 5 minutes.

To warm corn tortillas, wrap them in damp paper towels and microwave for 10-20 seconds or heat on a skillet for about 10-15 seconds on each side.

Assemble the tacos by spreading refried beans on each tortilla, adding the Portobello mixture, drizzling with chipotle pecan pesto, and sprinkling cilantro if desired.