Ground beef with onion is a flavorful combination called for in a number of recipes. Sometimes -- as with sloppy Joes or beef casseroles -- you can just toss diced onion into the pan with the meat while you cook it. This doesn't work for solid preparations, though, such as meatloaves, meatballs and hamburgers. In such instances, you need to thoroughly incorporate chopped onion into the ground beef before forming and cooking it.
Rub the onion between your fingers to remove the outer papery layer of skin. Discard the skin and lay the onion on a cutting board. Hold it still with your non-dominant hand and slice off the top 1/2 inch of the stem end with a sharp kitchen knife. Discard the severed piece.
Place the onion upright on the flat cut end. Hold it still with one hand, curving your fingers inward slightly, and cut the onion in half with a downward cut. Peel the rest of the skin and the tough outer layer of the onion off each half and throw the removed parts away.
Lay each onion half flat on the cut side. One at a time, hold them steady by pressing down on them firmly from the top. Make horizontal cuts almost, but not quite all the way, through to the root end. Make the slices as close together as possible for a fine dice or mince, which is the appropriate size for incorporating into ground beef.
Hold the onion still at the root end, curling your fingers inward a little. Make vertical cuts close together, beginning at the root end, but leaving the end intact. As you get close to the other end, grip both sides of the onion and press together to hold it steady. Rotate the onion 90 degrees, holding it together, and make perpendicular vertical cuts all the way through.
Unwrap the ground beef and remove it from its packaging. Place it in a large mixing bowl and break it up into small chunks with a cooking spoon.
Scoop the minced onion into the mixing bowl. Add in other desired aromatics, herbs and spices, such as minced garlic, finely chopped mushroom or bell pepper, salt, black pepper, basil, oregano, thyme or a spicy pepper powder.
Fold the onion and other aromatics, herbs and spices into the ground beef with your hands. Turn the meat over repeatedly and knead it continuously to thoroughly incorporate the other ingredients.
Shape your meatballs, meatloaf, hamburger patties or other preparation once the onion and other ingredients are dispersed evenly throughout the ground beef.