Tortellini Soup

Last night when I cooked the butternut squash and the spinach for the gratin, I reserved the cooking water, and I used it tonight to make a tortellini soup! I used onion and garlic sauteed in olive oil, spinach, collards, store-bought spinach-mushroom tortellini, cannellini beans, oregano, and the reserved broth. I served it with cheddar-garlic biscuits. It turned out pretty good!