Many years of watching cooking shows and practicing in the kitchen have led to the accumulation of many helpful tricks that you may not pick up elsewhere. Here are a few choice ones:
Cooking with oil
To check that oil has reached the right heat for cooking, splash a few drops of water into the pan. If the oil sizzles and spits, it is ready (just be careful not to burn yourself).
Marinating fish
Because of the delicate texture of some types of fish (salmon, tilapia ect...), marinating them in liquid for longer than 10-20 can make them soggy and crumble in the pan when cooking. A thick fish steak like tuna or swordfish can be marinated for significantly longer periods.
Washing strawberries
The best way to clean strawberries is to wipe them with a damp towel. They are porous by nature and will soak up a lot of liquid. If rinsed under running water and not eaten soon afterward, they can rot more quickly.
More tips will undoubtedly come, so stay tuned!
