Instructions

Set your oven to 300 F to preheat.

Prepare all your vegetables: Cut your onions in half and cut them thinly; there is no need to peel them. Do not peel your carrot, but cut it into thin slices. Likewise, thinly cut your celery and half your head of garlic crosswise. Crush the kombu and dried mushroom. Add all your cut vegetables to a baking sheet, together with your parsley and crushed kombu and mushrooms.

In a separate bowl, mix together oil, miso paste, and 2 tablespoons of water, then drizzle your mixture over your vegetables and toss to combine. Put in the oven to bake for about 60 to 75 minutes, or until very fragrant and the vegetables have shriveled, tossing halfway through to make sure they will not burn.

Once baked, take your vegetables out of the oven and add them to a large pot. Cover with 4 quarts of cold water and your peppercorns, and bring to a boil on the stove. Once it is boiling, bring it to a gentle simmer and let it cook uncovered until the liquid has reduced in half, which will take you anywhere up to an hour.

Leave your broth to cool down, then strain out all the solids, pressing on them to make sure you get all the liquid out. Discard your solids and use your broth for your soups.

Likewise, once completely cooled, you can also freeze it for up to 3 months to use when needed.