5whole15 g dried guajillo chilies, or a blend of dried chilis you like.
2teaspoonscrushed red pepper flakesrecently purchased—make sure they’re hot!
1cup240 ml flavorless cooking oil such as grapeseed, soybean, et cetera
1tablespoondried prickly ash / Szechuan peppercornsIf you use commercial Szechuan peppercorns, reduce this to 1 teaspoon as they're stronger than X. americanum.
3tablespoons(~10 g) ground mushroom powder-the bigger variety the better. Do not use dried woody polypores like chicken of the woods or dryad saddles
2large cloves garlic, (8 g) ends trimmed
½-inch piece (3 g) fresh ginger, coarsely chopped
1small shallot (18 g) coarsely chopped
2½ tablespoonsfermented black beansDouchi
Toast the guajillos in a 300°F (150°C) oven for 10 minutes, then cool. Break the stem off each chili and shake out the seeds. Discard the stems and seeds.
Crush the chilies in a mortar and pestle so that they're coarsely crushed (you don't want a powder here) then mix with the crushed red pepper and reserve. Combine all ingredients except the dried chilies and black beans in a blender and puree until smooth, about 30 seconds.
Pour the mixture into a small 2- to 3- cup (490–720 ml) capacity saucepan, add the guajillo or other chilis and crushed red pepper flakes, bring to a simmer, and cook on low heat until the liquid has evaporated, about 30-45 minutes.
Watch the mixture carefully, as you don’t want to burn it.
When in doubt, undercook it a bit as; you can always gently simmer it for a bit longer.
When the mixture is starting to separate, stir in the beans, cook for a few minutes more, then set aside the pan to cool off the heat, and marvel at how great the kitchen smells.
The sauce will last for a month in the fridge—longer if you make sure the solids are always covered by a layer of oil in the jar. Stir it before using.