In a pot, combine the chili peppers, red bell peppers, and apple cider vinegar. Cover the pot with a lid and cook for about 20 minutes or until the peppers have softened. In a colander, drain the pepper mixture and with the back of a wooden spoon, press on the peppers to extract any excess liquid.
Transfer the peppers to a food mill or a blender and puree. Press the puree through a sieve to remove the pepper skin. Discard the skin. In a saucepot, over medium heat, add the pepper puree and add the sugar a little at a time and mix until the sugar has dissolved. Continue to cook the mixture for about 40 minutes, stirring occasionally. Remove from the heat when the mixture resembles a jam texture. Allow to cool and transfer into jars.