Place all the ingredients for the Italian Sausage in a large mixing bowl and knead well with clean hands until evenly combined.
Place a 5½ quart saute pan or 8 quart stock pot over medium-high heat and add a few tablespoons of fat to it. Once the fat has fully melted, delicately add the sausage meat in chunks roughly the size of a ping-pong ball. No need to make fancy balls, just lift pieces from the bowl with your fingers, squeeze them lightly in the palm of your hand and then drop them in the hot fat.
Cook, stirring delicately with a wooden spoon from time to time, until the chunks of meat become brown and crispy. Try not to break the chunks of meat as you stir.
When the meat is nice and brown all around, lower the heat to medium, add the onion, garlic, celery and bell pepper stir and continue cooking until the vegetables are slightly softened, about 3-4 minutes.
Add the tomatoes, water, olives, parsley, oregano, salt and pepper, stir and bring to a simmer, then lower the heat to low and let the sauce simmer for about an hour, until it has thickened a bit and reduced by about one quarter.