I am planning on making a soup with Italian sausage, kale and potatoes as the main ingredients, in chicken stock. I bought a locally made and very nice sausage but it is pretty mild, I skipped over the part about using hot Italian sausage in the soup. I was going to add some red pepper flakes to compensate, there is not a lot of other seasonings in the soup. Would you suggest anything else to compensate? I have fennels seeds also which always seem classic Italian sausage to me but do not seem to be incorporated in the sausage I purchased.