Things you'll need: Sharp kitchen knife Cutting board Onion Step 1 Leave the root side of the onion intact. Step 1 Leave the root side of the onion intact. Slice off the other end of the onion. Step 2 Remove the papery skin as well as the first layer of the onion. Cut the onion in half, and place one half on top of a cutting board with the side flat down. Step 3 Make a series of vertical slits in the onion from the root down, making sure not to cut through the root end. Leave about 1/2" at the root end intact. Keeping the root end intact will hold the onion together while you're mincing. Step 4 to continue mincing the onion properly, begin working horizontally. Place the tips of your fingers firmly on top of the onion and, holding the blade of the knife horizontally, cut through the onion at several intervals to form a "grid." Step 5 if necessary, run your knife over the pieces until they're small and evenly minced. Step 6 Repeat the process to mince the other half of the onion.