Garden Chicken Cacciatore (in slow cooker)

I was looking for low-carbonate & high-protein meals and I found this recipe in a cooking magazine. Tried and we liked it. Simple, yummy and healthy.

2 pound boneless and skinless chicken breasts or thighs
1 onion, chopped
2 green peppers or broccoli (chopped)
1 can diced tomato, (Italian style, with oregano, basil and garlic), undrained
1 can (6 oz) tomato paste ( I didn't have tomato paste at home and I used salsa, still good)
3/4 cup low-sodium chicken broth
1/2 tsp salt
1/4 tsp black pepper
minced garlic,
2tbsp cornstarch
2 tbsp water

Place chicken in slow cooker. Add chopped onion, vegetables.
In a bowl, combine diced tomato, tomato paste, garlic, salt, pepper, pour over chicken and vegetables. Pour chicken broth over. Cover and cook on low for 6 hours.
Combine cornstarch and water, stir into slow cooker, cook until sauce is thickened.