On high heat: Mince and sauté the garlic and onions until they begin to sweat and brown. Add in the chopped mushrooms

Add in the mince meat. Use a wooden spoon to chop and separate the meat. Throw in some oregano and salt. You can adjust the flavour later to taste if needed

When the meat is almost fully brown, add the passata and chopped tomatoes to the pan. Reduce the heat to let it simmer. Now would be a good time to cook some pasta if that's what you're having this with.