Vegetarian Enchiladas with Butternut Squash and Black Beans

1 cup red enchilada sauce, homemade or canned 1 tsp olive oil 2 1/2 cups peeled butternut squash, cut 1/2-inch-dice salt and pepper, to taste 1 small onion, diced 3 cloves garlic, minced 1 jalapeno, seeded and diced 10 oz can Rotel tomatoes with green chilies 1 1/2 cups reduced sodium canned black beans, rinsed and drained 1/4 cup cilantro 1 tsp cumin 1/2 tsp chili powder 1/4 cup water 8 medium low-carb whole wheat flour tortillas 1 cup reduced-fat shredded Mexican cheese 2 tbsp chopped scallions, for garnish reduced-fat sour…