Yes, aromatics can be cooked in butter instead of oil. Butter adds a rich, nutty flavor that complements many dishes.
Cooking aromatics like garlic, onions, and ginger in butter is a common culinary technique. Butter, being a fat, effectively extracts the flavors from these aromatics, infusing the butter itself with their essence. This infused butter can then be used as a flavorful base for sauces, soups, or other dishes. The key difference between using butter and oil lies in the flavor profile and the heat tolerance. Butter has a lower smoke point than many oils, meaning it can burn more easily at high temperatures. Therefore, it's best to cook aromatics in butter over medium-low heat to prevent burning and to allow the flavors to meld properly. When the aromatics become fragrant and translucent (or lightly browned, depending on the desired flavor), they have sufficiently flavored the butter.
To prevent butter from burning when cooking aromatics, consider using clarified butter or ghee, which have higher smoke points due to the removal of milk solids. You can also add a tablespoon of oil to the butter to raise the smoke point slightly.