In a large skillet, cook chicken, half at a a time, in hot oil over medium-high heat until browned on all sides.
In a 4-1/2- to 5-1/2-quart slow cooker combine squash, green beans and tomato; sprinkle with garlic powder, oregano, pepper and thyme. Add broth and wine. Top with chicken. Cover; cook on low-heat setting 8 to 9 hours or on high-heat setting 4 to 4-1/2 hours.
Break up squash while serving. Top with cheese. Makes 6 to 8 servings.