Don't crowd your pan when frying foods. And don't turn the food until it is cooked thoroughly on one side.
When buying lemons for their juice buy the heavy ones, when buying them for the zest, choose the clean and yellow ones.
Sweat and drain eggplants and zucchini to remove extra water and bitterness.
Don't crowd your pan when frying foods. And don't turn the food until it is cooked thoroughly on one side.