1. Place squash in a microwave-safe bowl, cover and microwave on high until soft when pierced with a paring knife, about 3 minutes.
2. Warm oil in a large saucepan over medium-high heat. Add onion and garlic and cook, stirring often, until softened, about 3 minutes. Add turkey, chili powder, cumin and salt; cook, breaking up meat with a spoon, until meat is no longer pink, 3 to 5 minutes.
3. Stir in tomatoes, bring to a boil, reduce heat to low and simmer until tomatoes have cooked down and mixture has thickened, stirring occasionally, about 10 minutes. Add squash and beans; cook, stirring, until warmed through, 1 to 2 minutes longer. Serve hot.