To make homemade spaghetti sauce, you will need about 40 medium-sized Roma tomatoes. Many of the other ingredients are to taste, but you may also want to consider adding green bell peppers, carrots, onion, garlic, basil, thyme, oregano, wine, salt and pepper.
It is important to remove the skins and seeds of the tomatoes, as they will become chewy in the sauce, so begin by plunging the tomatoes into boiling water for about a minute. Remove them with a slotted spoon, and place them into an ice bath until they are cool enough to handle. Remove the peels with a knife, and remove the seeds by squishing the tomatoes in your hand until the seeds pop out.
Puree about 80 percent of the tomatoes in a food processor, and chop the remainder; the chopped portion will lend additional texture to your sauce. Sauté onion, bell pepper, chopped carrot and garlic in olive oil and butter for about five minutes. Add tomatoes, basil, thyme, oregano and wine. Bring to a boil, and then simmer for two hours.
Roma tomatoes, sometimes called paste tomatoes, are considered by some to be the best for making sauces. They have fewer seed compartments, thicker walls and less water surrounding the seeds. As a result, they produce a thicker sauce, which doesn't need to be cooked as long to boil off the excess water.