Unless missiles are raining down on your kitchen or there is a famine in your area, there's no defense for using garlic in a jar. Never. Ever. Learn how to peel and then crush, slice, and mince garlic quickly. There are a variety of techniques. Watch some videos on YouTube.
If you are desperate to save time, you may use canned tomatoes. But that should be a last resort. Fresh garlic and fresh onions are two of life's simple pleasures. Seriously.