Remember back in the 80s when olive oil was all the rage? You had to cook or douse everything with it. Then the tv chefs started to notice its shortcomings - that extra virgin wasn't very good for frying (but great for dressings) or for use in mayonnaise.
Remember when you could only cook with polyunsaturated or monounsaturated oils, otherwise you'd drop dead? Now I notice that tv chefs are not only using butter again, but lard and duck fat!
In the 90s, the big fad was balsamic vinegar - you had to use it on everything. Now, you hardly hear of it, and tv chefs are starting to rediscover plain old red and white wine vinegars.
What culinary fads do you see coming in/fading out?