Add the olive oil to a large skillet and warm over high heat. When oil is hot, add the red onion. Saute for 2-3 minutes until tender. Add in the garlic towards the end of the time.
Add in the beans, crushed tomatoes, salsa, nutritional yeast, cumin and red pepper flakes. Add in a few pinches of sea salt - to taste. Fold gently to combine. Allow to cook for two minutes, until the edges of the mixture start to bubble.
Turn heat down to medium. Push the bean mixture to the side and add in the spinach or kale. Press it into the hot pan to help wilt the greens. Cover with a lid, if desired to more quickly wilt the greens.
When the greens are warm and soft, gently fold them into the bean mixture. Turn off heat. Do a taste test and salt to taste if you want a bit more.
Warm your tortillas and prepare your guacamole. You can also simply slice your avocado.
Scoop the bean mixture into serving bowls and serve alongside the guac or avocado - and the warmed tortillas.
Finally, drizzle hot sauce over top. Drizzle something creamy over top too. This could be vegan ranch, vegan chipotle mayo or another vegan mayo or sour cream type mixture. DIY cashew cream works great too.