Directions

Put the tomatoes, butter and onion in a pot over medium heat. Once the butter is melted, stir to combine, then reduce the heat to low or medium (you want a slow and steady simmer) and cook for about 45 minutes. Stir occasionally, squishing the tomatoes against the side of the pot.

Cook pasta according to package instructions.

Remove sauce from heat, discard the onion and taste. Add salt if needed. Serve over cooked pasta.