In a large skillet, heat the avocado oil over medium heat. Add the finely chopped yellow onion and sauté for about 3-4 minutes until it becomes translucent. Then, add the minced garlic and chopped red bell pepper, cooking for an additional 2-3 minutes until fragrant.
Next, toss in the chopped sweet potato cubes. Stir well to coat them with the oil and aromatics. Cook for about 5-7 minutes, stirring occasionally, until they begin to soften.
Drain the soaked quinoa and add it to the skillet, mixing it in with the sweet potatoes and vegetables.
Add the vegetable broth or water, and bring the mixture to a gentle boil. Reduce the heat to low, cover the skillet, and let it simmer for about 15 minutes, or until the quinoa is cooked and the sweet potatoes are tender.
Once the quinoa and sweet potatoes are cooked, stir in the salsa, chili powder, sea salt, and drained black beans. Mix everything thoroughly and allow it to heat for an additional 5 minutes.
Once everything is heated through, taste and adjust the seasoning if needed. Serve your Mexican Vegan Black Bean & Sweet Potato Skillet warm, garnished with your favorite toppings such as avocado slices, cilantro, or a squeeze of lime.