Lumpfish eggs are dyed black to imitate the beluga sturgeon caviar. This dye rubs off if you have not taken the precaution to thoroughly rinse the eggs in a colander under cold running water. Once rinsed, you just have to drain the eggs on paper towels before garnishing a dish. The effect created by the black eggs is dramatic and very beautiful. There also is red lumpfish eggs.
If you don’t have a cookie cutter, use a tin can of similar size open at both ends.