Cut beef or mutton fat into small pieces
Remove any meat, blood, or connective tissue
Place the fat in a heavy pot or slow cooker
Add a small amount of water to prevent scorching at the start
Heat on low until the fat melts and the solids separate
Stir occasionally if using a pot
Keep the heat low and do not let it brown
Continue until the solid pieces become crisp and golden
Strain the liquid through a fine mesh strainer or cheesecloth
Pour the strained liquid into clean heatproof containers
Let it cool and solidify
Remove any remaining sediment from the bottom if needed
Store in a sealed container in the refrigerator or freezer