Heat olive oil, sauté garlic, onions, and ginger until soft and aromatic. Add contents of skillet to water. Add broth, shiitake, astragalus, and reishi. Simmer covered for two hours.
Remove from heat, allow to sit for two more hours.
Remove astragalus and reishi mushrooms. Reheat.
Add salt and pepper to taste, and cayenne powder if desired. (just enough to bring out a light sweat)