Bobby Flay doesn’t use much oil for cooking his burgers in cast iron — only a couple of teaspoons — and he chooses canola oil over other vegetable oils because it’s neutral in flavor. Canola oil also has a relatively high smoke point of roughly 400 degrees. Since Bobby puts his cast iron pan over high heat, choosing an oil like canola is ideal; it won’t alter the flavor of the simply seasoned ground beef (Bobby recommends just salt and pepper), and it also lets you cook at a high enough temperature that the burger achieves the perfect crust.
Canola oil, in addition to being Bobby’s go-to for cooking burgers, is also one of the oils that cast iron cookware producers Lodge recommends for properly seasoning cast iron, for the very same reasons it’s perfect for cooking burgers: canola oil won’t impart flavor to the food you cook in your seasoned cast iron, and you can cook at a high temperature without worrying about the smoking pan.
If you’re cooking burgers in cast iron using Bobby Flay’s method, you’ll want to make sure you avoid unrefined oils like walnut, hemp seed, or sesame oil for two reasons. First, they’re immensely flavorful, which makes them perfect to drizzle on soup or use in a salad dressing, but also means they’ll flavor your burger. Second, their low smoke point means you’ll either have a smoky mess or you’ll have to lower the cooking temperature, which can hinder your ability to properly crust the burger’s exterior.