I think there is a real debate in professional kitchens between chefs. Cooking with butter verses a blended olive oil can be a tough choice. If you are a traditional French chef, there is no choice. You choose clarified butter. If you come from the olive country in Italy, then you use oil. I think if you are a versatile cook, you use both. Here, I just want to touch on a few basics on what I like to use and why.
Butter will burn if it gets too hot because the solids of the butter will cook if it isn’t clarified. Clarified butter is just slowly cooking the impurities out of the butter by skimming the top and straining the clear liquid on top of the white solids that settle on the bottom. You do lose some richness and flavor by using clarified instead of straight butter. I also like to use lightly browned butter in some saute dishes to give them a more nutty flavor.
Olive oil has so many uses for cooking. Blended oil which is usually 25% olive oil and 75% vegetable oil is my favorite for pan frying. It wont smoke until it is very hot so you can get a nice crispy sear on meats and vegetables. I do think blended oil is a healthier option and is ‘vegan’ friendly. (it is funny to see old French chefs freak out when they get a vegetarian much less a vegan!)
Overall, it is all about taste and desired results. For a cleaner flavor, I like olive oil. I like butter for vegetables the most because it enhances their flavor. So for delicate fish, I like oil. I also use it as a way to separate French and Italian dishes. Some Italians say that butter is only for unrefined palates. I wouldn’t go so far to say that. I would say some people are butter crazy. I swear, you almost cannot serve Lobster without butter, people will always ask for the butter. To be honest, I don’t think butter serves lobster as well as cream but that’s another discussion. A fun thing to try is cooking the same thing, one portion using blended oil and another using clarified butter. See if you can pick up the difference.