1. Mix the yeast with 1 1/2 cups warm water and set aside for 8 to 10 minutes. Mix together the flour, olive oil and salt in a bowl using an electric mixer. With the speed on low, drizzle in the yeast/water mixture and mix until totally combined. Cover the bowl with a towel and set in a warm, draft-free place. Allow to rise for 1 to 2 hours.
2. Pour the black beans into a saucepan. Add the taco seasoning and heat up the beans over medium-low heat. Use a potato masher to mash the beans to the desired texture. Continue cooking/heating over medium-low heat, stirring occasionally, until the beans are no longer runny (they should be the texture of refried beans). Set aside.
3. In a small skillet, heat the rapeseed oil over medium heat. When hot enough to fry, drop in the tortilla strips in batches, frying them quickly and removing them from the oil with a fork when crisp--30 to 45 seconds per batch. Transfer to a paper towel-lined plate. Set aside.
4. Position an oven rack in the bottom position in the oven. Preheat the oven to 260°C. Oil a baking sheet with some olive oil.
5. Remove half of the pizza dough from the bowl. (Place the remaining half in a large plastic bag and refrigerate, saving it for another use.) With your hands, spread the dough out on the oiled baking sheet, making sure it's relatively thin. Spread a layer of refried beans all over the pizza crust. Sprinkle the grated Cheddar and Monterey Jack over the top. Place the baking sheet on the bottom rack in the oven and bake for about 25 minutes, watching to make sure the crust doesn't burn. Remove the pizza from the oven and sprinkle on the shredded lettuce, diced tomatoes and coriander leaves.
6. Mix together the sour cream and hot sauce in a small bowl, adding enough hot sauce to make the mixture pourable. With a spoon (or you can put it in a pastry bag), drizzle the mixture over the finished pizza.
7. Sprinkle with the tortilla strips. Cut into squares and serve immediately with good-quality salsa.
8. If using leftover homemade black beans, reheat in 1/2 tablespoon melted butter.