Pour the tomatoes into a 5 -6 quart crock pot. Use a potato masher or your hands (if you want to be one with the tomatoes) to crush the tomatoes.
In a large skillet, heat a bit of the olive oil. Crumble the sausage meat into the skillet. Discard the casing. Brown the sausage lightly. When it is barely cooked through add it to the slow cooker.
Add a little more olive oil to the pan and add the finely chopped chicken meat. You want this to brown, so if you need to, do it in two batches. Again we are looking for some color and barely cooked. Add this to the cooker as well
Add the remaining olive oil to the pan and add the onions and garlic. cook these until they are just getting translucent and lightly browned.
Add the tomato paste to the onion mixture along with a splash of stock. Cook for 3 to 5 minutes.The onions should be coated and the mixture should be a lovely russet color.
Add this to the cooker along with the parsley and Italian herbs.
Stir everything together and cover the pot. Set the temperature on low and let it go. 8 -10 hours should do it.
When you feel that it can’t get any more wonderful, turn off the pot. If it seems to thick, add a little more stock. .
Cool slightly. Divide the gravy into 3 containers. Freeze 2 and put the other one in the refrigerator for dinner tomorrow.