How to heat oil or fat, determine when it's hot and how to keep the right temperature
To pan fry or sauté foodstuffs, use (preferably) a frypan or skillet. A pot may do, too, but you may need to increase the amount of oil or fat, and stir more often (to avoid sticking of the pieces to the bottom of the pot).
You can use any kind of edible vegetable oils (canola, colza, sunflower...), or butter, or margarine (with a fat content of at least 80%).
Put the pan on the stove and add one or more tablespoons of oil (and/or butter or margarine), according to the following table
| pan bottom diameter | coated pan | uncoated pan | pot |
| 15 cm | 1 | 2 | 3 |
| 20 cm | 2 | 4 | 4 |
| 25 cm | 3 | 5 | 5 |
The idea is that for uncoated pans and pots, the entire bottom should be covered with a thin layer of oil or fat, and in the case of a pot, you may need additional oil because the food items are likely going to be stacked on top of each other. Pans with a teflon or ceramic coating need less oil, but they get damaged easily, so you should never use a metal tool directly inside such a pan.
Turn on the heat at maximum and wait next to the pan for the oil or fat to get hot. To check whether it's hot enough, let a drop of water fall into the pan. If it makes a sizzling sound, it's hot enough. You can now reduce the heat to around two thirds of the maximum and add the food items according to your recipe. In case you see smoke raising up from a pan that contains only oil or fat, it means that it's too hot: Turn off the heat immediately (and on an electric stove, or a wooden fire, remove the pan from the hotplate, unless you use induction, in which case this step is not necessary). If most of the oil or fat is still in the pan, you can add some more oil and then start cooking according to you recipe (attention, spalshes of oil!); if most or all of your oil or fat has already evaporated, leave the pan as it is until it has cooled down (may take 15 min) and then start over. Never try to cool down hot oil with water!
While frying your food, you can estimate the temperature from time to time: if a drop of water produces a sizzling sound, the temperature is OK, but if the sound lasts less than 0.2 sec (resembles more a 'bang' than a 'shhh'), it's too hot and you need to reduce the heat.