Onion slices can be long curved strips or semicircles. Choose the shape your recipe calls for and keep the thickness consistent so the slices soften together. Slicing is a different task from dicing: you do not need horizontal cuts through the onion half.
Step by step
Peel and halve the onion
Trim the stalk end, remove the papery skin and cut the onion in half through the root. Put each half cut side down. Remove the hard root section before making slices that need to separate fully.
Choose strips or half-rings
For curved strips, slice lengthwise from the former stalk end towards the root end. For half-rings, cut across the onion half, perpendicular to that direction. Neither method requires cutting into the onion sideways.
Image by JustRecipesKeep the thickness even
Hold the onion with curled fingertips and use steady downward slicing strokes. Move your guiding hand back as you cut. Turn the final small piece onto a stable side rather than trying to hold it upright.
Separate the layers
Loosen the slices with your fingers before adding them to the pan. Keep thin and thick pieces apart if they will need different cooking times.
Choosing a useful thickness
Very thin slices soften quickly and can catch in a hot pan. Thicker strips retain more shape during longer cooking. Follow the dish’s intended texture rather than making every onion paper-thin. If you need whole rings, keep the peeled onion whole and cut a small flat base so it cannot roll.
