Making a quick pasta sauce when there is no parmesan or cream in the house

It's a pasta night and the fridge contains no cream or parmesan. I do have garlic, olive oil, canned tomatoes, a lemon and a few herbs. Instead of treating it as an emergency, I'm thinking of a simple glossy sauce using starchy pasta water and olive oil, then something acidic for balance. What pantry-based pasta sauce is worth learning by feel rather than following a full recipe?