Combine tomatillos and jalapenos on a baking dish. Roast under broiler 5 minutes or until skins blacken; turn over and roast for 5 more minutes.
Melt butter in pot over medium heat. Add onion and garlic, fry until soft and a bit charred. Add flour and stir. Add tomatillos, jalapenos, cilantro, cream and water. Blend with a stick blender (if you don't have a stick blender, let cool and pour into a regular blender). Taste and add salt if needed.
Heat olive oil in pan. Add zucchini, yellow squash, eggplant, and mushrooms; cook until softened and slightly brown. Add spices, salt and pepper.
Heat the oven to 350 degrees. Coat the bottom of a rectangular baking pan with the sauce. Heat the vegetable oil over medium heat in a heavy pan. One by one, fry the tortillas in the oil to soften, shaking off any excess. Put on a plate and add some of the vegetables, and some of the grated cheese. Place in the pan seam-side down.
Pour the rest of the sauce on top of the enchiladas, and crumble the queso fresco on top. Put in the oven until the cheese gets a touch melty -- about 15-20 minutes. Cover if it's starting to burn.