Begin by combining onion, celery, garlic, oregano, red pepper flakes, and parsley in food processor, until evenly chopped.
In a pan on medium heat, add your olive oil.
While pan is heating, remove casing from sausage.
Once pan has heated, add sausage, cooking 4-5 minutes until browned.
Add ground turkey, frying until nearly cooked, add salt & pepper.
Transfer sausage, and turkey to a bowl.
In the same pan, turn it up to medium-high heat, adding vegetable mixture once heated, cooking 8-10 minutes, until vegetables begin to turn a golden colour.
In a bowl, stir 1 tablespoon tomato paste, with 1 cup of water, adding to vegetables (after they have cooked for 8-10 minutes).
Simmering until nearly all liquid has evaporated.
Add sausage, and turkey to pan, along with pureed tomato, and one cup of water.
Simmer until sauce is no longer runny, about 10-15 minutes.
Once sauce is done reducing, add salt & pepper to taste.
Boil pasta for about 12 minutes until desired tenderness.
Place pasta in serving dishes, top with ragu, and sprinkle shredded parmesan cheese to top it off.