Slicing food uniformly ensures even cooking, preventing some pieces from being overcooked while others remain undercooked, leading to a better overall texture and flavor.
When grilling or pan-frying, heat is transferred to the food's surface. If the pieces are of varying thicknesses, the thinner pieces will cook much faster than the thicker ones. This results in some pieces becoming dry, burnt, or overcooked, while the thicker pieces might still be raw or undercooked in the center. Uniform slicing ensures that each piece receives a similar amount of heat and cooks at a similar rate. This leads to a more consistent texture and flavor profile across the entire dish. For example, if you're stir-frying vegetables, uniformly sliced carrots, peppers, and onions will all reach their optimal tenderness at roughly the same time, creating a harmonious blend of textures. Similarly, uniformly sliced chicken breasts will cook evenly, preventing some parts from drying out while others remain pink.
Use a mandoline or a sharp chef's knife and a steady hand to achieve uniform slices. A consistent thickness will dramatically improve your cooking results.