Clean the nicked area of your dish by soaking a cotton ball in rubbing alcohol. If the nick is very small, use a cotton swab dipped in alcohol. Dab the area carefully so you do not make the nick any worse.
Mix a very small amount of oil-based paint and epoxy; do not add too much paint. The mixture should be creamy, not watery. The oil-based paint should match the color of the area you need to fill. Dip a toothpick into the mixture and apply it carefully to the nick in the dish. Let the paint and epoxy filling dry over night.
Touch the filling to be sure it is dry. If it is still tacky, let it dry for another few hours. If it is dry, remove extra filler with fine sandpaper. Do not rub so hard that you scratch or remove all the filler. You can also use the sandpaper to form the filler into the shape you want.
Add glaze with a feathery paint brush. The glaze should be applied thinly. Let it dry for a few more hours unless the glazing directions indicate otherwise.