Drain and rinse the black beans. Place into a small pot with water, coriander, cumin, chili powder, salt, garlic powder, chili powder and smoked paprika. Mix and cook over low heat. Stirring every few minutes.
Meanwhile, make the Creamy Sauce. Place the yogurt, cilantro, garlic, jalapeño, lime juice & zest and salt into a blender or food processor. Pulse until smooth. Place into a container and let chill in the fridge. Can be made up to three days ahead of time.
Next, make the zucchini and squash. Slice into 1/2 inch thick pieces and cut into half moons or quarters. You want them to be bite sized pieces. Place into a skillet with butter or oil over medium heat. Cook for about 5-6 minutes, turning once, until tender and just starting to brown.
Warm tortillas over stove or in oven. Smear black beans into tortilla and top with zucchini and squash. Drizzle with Creamy Spicy Green Sauce, top with red onions and cheese and eat warm.