Slow-Cooker Rustic Chicken Stew

2 pounds boneless, skinless chicken breasts, washed, patted dry, cut into 1-inch cubes
3 medium onions, peeled, quartered
2 large carrots, peeled, cut into 1-inch-thick slices
2 potatoes, peeled, cut into 1-inch cubes
2 cans (14 ounces each) fat-free, 1/3-less-sodium chicken broth
1 teaspoon celery seed
1 teaspoon dry thyme leaves
1/2 teaspoon black pepper
8 ounces mushrooms, cleaned, halved
1 cup frozen corn
1 cup frozen peas

In a 5-to-6-quart slow cooker, combine the chicken, onions, carrots, potatoes and broth. Stir in the celery seeds, thyme, pepper, mushrooms and corn. Cover and cook on low until the chicken is done and the vegetables are tender, about 7 to 9 hours, or on high for 4 to 6 hours. Stir in the peas and cook until they're done, about 15 to 30 minutes.