HOW TO MAKE SCHMALTZ
• You can make schmaltz with any amount of chicken skin and fat. Chop the skin and fat finely, to ensure better rendering.
• In a frying pan over gentle heat, place chopped fat and skin in a small amount of water (about 1/4 cup water to 2 cups skin and fat, or what is removed from 8 chicken thighs).
• Browning begins once the water and moisture have cooked off. This is when you add 1 Spanish onion, diced.
• The fat should be clear and yellow, not brown, so keep the heat low.
• The brown bits of skin and onion are known as the gribenes. They will remain in your sieve as you strain off the fat. (Use a fine mesh sieve or straining cloth.)
• Reserve the gribenes and strained fat separately — both can be kept in the refrigerator for about a week or in the freezer for about six months. This process will yield about 1/2 cup fat and 1/2 cup gribenes.
From "The Book of Schmaltz," by Michael Ruhlman.