Combine red bell peppers, Serrano pepper, and lemon zest and juice. In a separate bowl, whisk the pectin into the sugar. Stir into the pepper mixture. Place in a saucepan. Bring to a boil and continue boiling for 5 minutes, stirring constantly. Remove from heat and puree with an immersion blender or regular blender.
Place in clean prepared jars and close tightly. Invert the jars and let sit at room temperature for 24 hours. After 24 hours, flip jars back over and refrigerate.
Refrigerate for up to 6 months.
Serve as a spread on crackers or bread, with goat and cream cheese, and as a glaze on fish, chicken, and pork.