Heat olive oil over medium heat. Saute garlic and red pepper flakes for 1 minute stirring constantly. Add onion, carrots, celery and sprinkle with salt and pepper saute 8 – 10 minutes stirring occasionally. Add sausages and saute another 3 – 4 minutes until the sausages start to brown. Add zucchini and saute another 2 minutes. Add the Italian seasoning and stir for 1. Add the tomato sauce, diced tomatoes, white beans and chicken stock. Bring to boil and let simmer, uncovered, for 10 – 15 minutes. Add peas and heat for 1 minute, then add the spinach. Serve in bowls with grated cheese on top.