Chicken Casserole With Potato Dumplings

• 4 tomatoes (peeled)
• 2 chicken breasts with the bones
• 2 garlic (cloves minced)
• 1 salt and pepper
• 1 potato
• 1/2 onion (chopped)
• 1/2 bell pepper (chopped)
• 950 ml chicken stock
• 210 gr mozzarella cheese (diced)
• 180 gr flour