How to Make It
In a large saucepan, combine all of the ingredients except the salt. Cook over low heat until all of the vegetables are falling-apart soft, about 4 hours; let cool slightly.
Drain the vegetables in a fine sieve set over a heatproof bowl; don’t press on the solids. Transfer the vegetables to a blender, add 1/4 cup of water and pulse until finely chopped. With the machine on, gradually drizzle in 2 cups of the cooking oil and puree until smooth and slightly thick (reserve the remaining cooking oil for another use). Season the hot sauce with salt and let cool completely before serving.