chicken in garden gravy

Ingredients

• 1 cup coarsely chopped sweet onions
• 1 cup coarsely chopped celery
• 1 cup sliced white mushrooms
• 1 large garlic clove, finely chopped
• 1/2 teaspoon salt
• 1/4 teaspoon freshly ground black pepper
• 1/2 teaspoon dried thyme or 2 sprigs fresh thyme
• 1 whole chicken, cut up
• 1/4 cup butter, melted
• 1 pound zucchini, thinly sliced or 1 pound fresh green beans
• 2 lemons, thinly sliced
• 2 tablespoons cornstarch
• 1 1/2 cups chicken broth