Remove tops, ribs, and seeds from peppers (for a very hot paste, leave jalapeño seeds), and chop them with a meat grinder or food processor.
Simmer for 15 minutes with just enough water to keep them from burning.
Mix in the salt and put the pepper pulp in large shallow noncorroding trays or containers, cover with cheesecloth to keep out insects and dirt, and set in direct sunlight for several days until reduced to a paste, stirring every day.
Spoon into clean jars, cover with a film of olive oil, tie cheesecloth over jars, and store.
The pepper paste will keep several months at room temperature.