Place parsnips in a saucepan and cover with water. Simmer until the parsnips are soft, about 1 1/2 hours. The reduction of liquid will result in flavor intensity. Pass through a strainer, discard the solids, and season with salt.
For each serving place two or three pieces of maitake mushrooms, and a few sprigs of epazote into a small saucepan. Cover with the hot parsnip broth, and simmer for 3 minutes. Finish with 4 or 5 fava beans and a tablespoon of olive oil. Simmer for 1 minute. Remove the epazote and discard.
To serve, place in a small serving bowl, and garnish with a fresh sprig of epazote.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.