Turn the oven on to broil. Arrange the red and jalapeño peppers on a sheet pan. Place them under the broiler and cook for 10 to 15 minutes until just charred. Turn the peppers over and broil an additional 10 to 15 minutes. When the peppers are just blackened on all sides, remove them from the oven and cover them with foil so they can steam. Allow them to cool for 30 minutes.

While the peppers are cooling, bring a large pot of water to boil. Using a sharp paring knife, make an X in the skin of the bottom of each tomato. Place them in the pot of boiling water. Boil for 1 or 2 minutes until the skins just start to split. Remove the tomatoes to a colander and rinse under cold water. Peel the skins off and roughly chop. Set the chopped tomatoes aside.

Remove as much of the skins and seeds from the cooled peppers as possible. Place the peppers in a food processor or large blender.

Add the tomatoes, onion, and olive oil to the food processor or blender. Process everything at high speed or blend everything on the low-medium setting of your blender until the mixture resembles a chunky sauce similar to relish or chutney. You might have to do this in batches.

Place a large heavy pot over medium-low heat. Pour the pepper and tomato mixture into the pot. Stir in the salt and sugar. Cook uncovered for 1-1/2 to 2 hours, stirring frequently.

Clean six 8 ounce mason jars and lids with soap and hot water. Rinse all of them with boiled hot water to sterilize.

After the lutenitsa has thickened and reduced by half, run a wooden spoon from the side of the pot towards the center. The valley made by the spoon should not fill in immediately. That’s how you will know it is finished cooking. Allow it to cool.

Place the lutenitsa in the clean jars. Seal the jars and store in the refrigerator until ready to serve. Enjoy as a spread, dip, or condiment for other Bulgarian dishes.