Never Step Away From The Pan While Cooking Garlic
Whether you're making garlic bread, a pasta dish, or the beginnings of stir fry, you may find yourself standing at the stove with garlic in a pan. Regardless if the garlic is chopped, minced, smashed, or sliced, it should be handled with care once it connects with your heat source. Because garlic is an allium that has low water content, it cooks very fast. Where onions have a lot more water and can cook over medium to high heat for a few minutes without burning, garlic tends to have this issue much faster.
While some recipes begin with a mirepoix (carrots, onion, and celery) to add a depth of flavor as they caramelize, you can actually hold off on adding your garlic until later in the cooking process. Garlic will permeate your dish with its flavor right away, so you don't need it to cook along with your other ingredients for as long. With that said, burnt garlic has a very bitter flavor and can ruin your entire dish so you absolutely don't want this to happen.
Watch it carefully
If you are cooking a recipe or using a culinary technique that calls for garlic at the jump and you're starting with it in a pan with butter or oil, be sure to cook it over medium-low heat and only until it's fragrant. Also, garlic that hits the pan can cook in about 30 seconds, so leaving it unattended is a big no-no. While you can generally leave some ingredients like meat or other veggies simmering in a pan and begin preparing another ingredient, garlic is one ingredient you want to keep a close watch on.
The exception to this rule would be if you are adding whole garlic cloves to a braising dish where they will slow cook in liquid, making garlic confit, or adding chopped garlic to an established sauce. This is also true if you are roasting garlic cloves still in their paper-like casings or if you've cut the top off the bulb and are roasting it in its entirety. These are instances where you can just set and forget your garlic. But in any instance where garlic comes into direct contact with a heat source, watch over it vigilantly.