In a saucepan, melt three tablespoons of the butter. Add garlic and sauté for a few minutes without browning.

Stir in flour, cooking two to three minutes.

Whisk in milk. Bring to a boil for three to four minutes, stirring constantly to make it smooth.

Stir in tomatoes, tomato paste, salt, pepper, and pepper flakes.

Add the hot cooked pasta to the tomato sauce mixture.

Stir in remaining two tablespoons butter and Parmesan cheese. Sprinkle with parsley and green onions. Serve warm.