In a large skillet, heat 1 tablespoon of extra-virgin olive oil over medium heat. Add the sliced onion and sauté until translucent, about 5 minutes.
Add the chopped poblano pepper and sliced cremini mushrooms, cooking for another 5-7 minutes until they soften.
Stir in the chili powder, ground cumin, sea salt, and chopped garlic. Cook for an additional minute until fragrant. Next, add the cooked black beans and pickled jalapeños, mixing everything thoroughly. Remove from heat and set aside.
Warm the corn tortillas in a dry skillet or wrap them in a damp towel and microwave for about 30 seconds until pliable.
Preheat your oven to 375°F (190°C). Lightly grease a baking dish with olive oil. Take a tortilla, add a generous scoop of the vegetable and bean mixture, then roll it tightly and place it seam-side down in the baking dish. Repeat with the remaining tortillas and filling.
Pour the enchilada sauce evenly over the assembled enchiladas, ensuring they are well-coated. Cover the dish with foil and bake for 20 minutes.
After 20 minutes, remove the foil and bake for an additional 10-15 minutes until bubbly and slightly golden.
Once out of the oven, let the enchiladas cool for a few minutes. Top with your choices of diced avocado, sliced radishes, diced red onion, chopped cilantro, and additional jalapeños for an extra kick. Serve with lime wedges on the side.