3 red bell peppers, finely chopped
2 jalapeño chiles, seeded and finely chopped
1 cup sugar
1 1/2 teaspoons crushed red pepper flakes
1/2 teaspoon kosher salt
1/4 cup liquid pectin
1 tablespoon fresh lemon juice
3 cups cranberries, fresh or frozen and thawed
Combine peppers, chiles, sugar, red pepper flakes and salt in a heavy wide pot over medium heat and bring to a simmer, stirring to dissolve sugar. Stir in pectin and lemon juice. Reduce heat and simmer gently for 10 minutes.
Stir in cranberries and simmer gently until they burst and juices thicken, about 10 minutes longer. Transfer jelly to a jar, let cool, and cover. Will keep for up to 3 weeks in the refrigerator.