In a large saucepan, combine 1/2 cup chopped onion and 2 tablespoons each extra-virgin olive oil and butter over high heat. Cook until golden, then stir in 3/4 pound ground beef and cook for 5 minutes; season with salt. Add 1/2 cup white wine and cook for 2 minutes. Stir in 2 cups chopped canned peeled tomatoes with their juice, season with salt, bring to a simmer and cook for 1 1/2 hours. Add 1/3 cup grated parmigiano-reggiano cheese when tossing with pasta. Makes 2 1/2 cups.