This is an excellent recipe by one of my favourite cooks, Ina Garten, on foodnetwork.com. Find the original page here.
1 tablespoon good olive oil
1 cup chopped yellow onion (1 onion)
1 1/2 teaspoons minced garlic
1/2 cup good red wine, such as Chianti
1 (28-ounce) can crushed tomatoes, or plum tomatoes in puree, chopped
1 tablespoon chopped fresh flat-leaf parsley
1 1/2 teaspoons kosher salt
1/2 teaspoon freshly ground black pepper
Heat the olive oil in a large (12-inch) skillet. Add the onion and saute over medium heat until translucent, 5 to 10 minutes. Add the garlic and cook for 1 more minute. Add the wine and cook on high heat, scraping up all the brown bits in the pan, until almost all the liquid evaporates, about 3 minutes. Stir in the tomatoes, parsley, salt, and pepper. Cover, and simmer on the lowest heat for 15 minutes.