I hardly ever mix garlic and onion in a recipe, and only then under protest from Mrs Steve. My quick pasta tomatoey sauces don't contain onion, just garlic, except for Marcella's onion and butter sauce, which is a definite one-off. There's no garlic in that one, of course. I don't like oniony clagginess in tomato sauces. It's grand to muck about with bolognese-type ragù to suit your own taste, but most, if not all, authentic Italian recipes don't use garlic. And I always use a mixture of minced beef and pork, never just beef alone.