Fra Diavolo Sauce:

Cup of Yum
1. Add the oil, onions, chili flakes and salt to a large, shallow pan. (Use a 12" pan or larger, see recipe notes.) Cook the onions over medium heat until they begin to brown (~5 min). Add the garlic and cook 1 more minute, or until the garlic is fragrant.
2. Add the tomatoes, water, and oregano to the pan. Increase the heat to medium-high and bring to a simmer.
3. Simmer the tomatoes for 20-25 minutes, or until most of the water has evaporated and the sauce has thickened.Taste the sauce and add more chili flakes, salt, or oregano if desired. Simmer 1-2 more minutes if you added more seasoning.
4. While the sauce simmers, bring a large pot of salted water to a rolling boil. Add the mixed seafood and cook for about 2 minutes. (If the seafood mix includes shrimp, cook until the shrimp turn pink.)Use a mesh sieve, skimmer or slotted spoon to remove the seafood from the water into a colander. Rinse with cold water to stop the seafood from cooking. Place the seafood in the fridge until your sauce is ready.(Do not discard the hot water.)
5. Add spaghetti to the large pot of boiling water.Cook spaghetti according to package directions.Add the cooked spaghetti to the pasta sauce and toss to coat.Add the seafood to the pasta and toss again.  Serve immediately.