Begin to thaw frozen catfish beforehand.

Bring a large pot of water to a boil.

Salt water with ¾ teaspoon of salt

Add the spaghetti and cook according to package directions.

Cut catfish fillets into bite-sized pieces.

Drain pasta, setting aside 1 cup of the pasta water.

Toss the spaghetti with oil and set aside.

Thinly slice 2 cloves of garlic.

Drain and crush canned tomatoes with a fork.

Add the oil, garlic, ¾ teaspoon salt and crushed red pepper to a large skillet over medium-high heat.

Once the oil begins to simmer, add the tomatoes, 1 cup reserved pasta water and oregano.

Bring to a high simmer and cook until the sauce thickens but is still loose, 12 to 15 minutes.

Add the fish and olives and cook, stirring occasionally, until the fish is cooked through and flaky, 3 to 4 minutes.

Add the spaghetti and parsley.

Toss to combine and divide among four bowls.