
Bring ham, garlic, red pepper flakes, salt, and 1 quart water to a boil in a large saucepan. Reduce heat and simmer, skimming foam from surface as needed, 1 hour.
Strain through a fine-mesh sieve into a medium heatproof bowl. Pick out ham and reserve for another use; discard remaining solids.
Do Ahead: Potlikker can be made 5 days ahead. Let cool. Transfer to an airtight container and chill, or freeze up to 3 months.