If you're simply guessing which oil to use for whatever's on tonight's menu, you might be sabotaging your own meal. And worse, you could be wasting expensive olive or walnut oil only to watch it burn up in the air fryer or under the broiler's fierce heat. Not all oils are created equal. That expensive variety you drizzle over salad may not be built for searing, and it's affecting your recipe's final taste, along with your monthly food budget.  High-heat cooking methods such as  frying or searing  are best done with neutral oils that feature a higher smoke point -- canola, avocado or grapeseed, to name a few. Olive oil and lower smoke point oils shine in dressings, slow cooking and sautes, where the rich flavor can stand out without burning and enhance the protein or vegetables.  For baking, some oils also lend moisture, while others add nutrition or depth when left uncooked.…