Add tomatillos, garlic, onion, jalapeno, coriander, oregano, coconut milk, salt and pepper to a blender and blend until smooth.
Pour into a sauce pan and bring to a simmer. Let that simmer, stirring occasionally, for about 10 minutes, until the flavor has developed. Set aside to cool.
Heat oil in a large pan over medium heat. Add sweet potato, squash, corn, beans, cumin, paprika, garlic powder, salt and pepper and stir to mix evenly. Cook for about 5 minutes, stirring regularly, until starting to brown.
Preheat oven to 350 degrees F. Lightly grease a 9×13 glass baking dish. One at a time, dip a tortilla into the sauce and then fill with a scoop of the filling and roll. Repeat until dish is full or you run out of filling.
Pour remaining sauce over the top. Cover with foil and bake for 25-35 minutes until filling is tender. Top with diced onion and/or cilantro and serve.