Start With Washing and Sorting
Every prep job starts with cleaning the ingredient properly before you cut it. Leafy greens (lettuce, spinach, rocket) should be rinsed in cold water a few times, changing the water until no sand or soil settles at the bottom. Root vegetables (carrots, potatoes, beets) are better scrubbed with a brush, since soil can cling deep into the pores.
Do not use detergent to wash fruit and vegetables; residue from a product not made for food can be harmful once eaten. Rubbing under running water is enough to remove most surface residue.
Practical Tip
You may notice a natural waxy coating on an apple's skin when washing it; that is the fruit's own protection and is not harmful — scrubbing it under water is enough.
Choose the Right Cutting Technique
How you cut something decides both its cooking time and how it looks on the plate. A julienne cut gives thin matchstick strips around 3 mm thick, suited to quick-cooking sautés. A brunoise gives tiny cubes with 3 mm edges that distribute evenly through sauces and soups. Chiffonade means rolling leafy herbs and slicing them into thin ribbons — ideal for basil and mint.
When holding the knife, use the claw grip: curl your fingertips inward so the flat side of the blade rests against your knuckles. This way the blade meets your knuckle, not your fingertip.
Ingredients cut to uneven sizes never cook evenly — one piece stays raw while another turns to mush. Care in the cut is half the battle in cooking.
Prevent Browning (Oxidation)
Apples, avocados and potatoes darken once cut and exposed to air; this is an enzyme reacting with oxygen, not spoilage. Rubbing a little lemon juice on the cut surface, or dropping the pieces into acidulated water (1 tablespoon of lemon juice per litre of water), slows the browning down.
The most reliable method is timing: cutting close to when you will cook, rather than long before, keeps browning to a minimum.
Treat Fruit Differently From Vegetables
Fruit is generally softer than vegetables and gets more delicate as it ripens; press gently on the board and avoid heavy knife strikes so it does not bruise. Thin-skinned fruit like strawberries and grapes should be dried thoroughly after washing, since leftover moisture speeds up mould.
Hard-shelled vegetables like pumpkin or celeriac need a large, sturdy knife and a stable cutting surface; cutting a hard vegetable on a slippery board is one of the most common causes of cut injuries.
Plan Prep Ahead (Mise en Place)
The mise en place principle used in professional kitchens means having every ingredient washed and cut before cooking even starts. It prevents the burning and overcooking mistakes that come from hunting for an ingredient mid-cook.
Prepped vegetables keep best wrapped in a damp paper towel inside an airtight container in the fridge; cut vegetables left out in the open both dry out and lose nutrients faster.