Chop the red and green bell peppers and onions.

Place chopped peppers and onions in a bowl.

Pour boiling water over the vegetables and let stand for 5 minutes.

Drain off the water.

Cover the vegetables again with boiling water and let stand for 10 minutes.

Pour the vegetable mixture into a muslin bag and drain overnight.

In a large pot, combine the drained vegetables, vinegar, sugar, and salt.

Boil the mixture for 20 minutes, stirring occasionally.

While hot, pour the relish into sterilized jars.

Seal the jars immediately.