Heat 2tsp oil in a sauce pan; add red pepper flakes, onions and garlic and sauté until onions are lightly browned around the edges, about 5 minutes.
Add the soy chorizo and cook for 2-3 minutes, stirring constantly.
Next add tomato paste, cayenne pepper, salt and mix well. Cook for another 2-3 minutes. Sprinkle some water if the mixture starts to stick to the pan.
Add spinach, salt and black beans; cover covered until spinach wilts and beans are heated through, about 5-6 minutes.
Warm taco shells and place 2-3 tbsp of filling in the middle, top with your favorite garnishes and serve.