Put them in a large pot with dried mushrooms and add water to cover plus about one inch.
Bring to a boil, lower heat and simmer on very low heat, covered, for at least 1 1/2 hours. It will cook down; you can add a little more water if you like but it will be more flavorful if you don't add any more liquid.
Remove from heat and let cool slightly.
Strain broth into a clean container, using a fine mesh strainer or a strainer covered with cheesecloth.
Add poultry seasoning and Kitchen Bouquet if using and stir.
Add salt and pepper to taste.
Recipe Notes
*To make your own oven-dried mushrooms, spread cleaned and sliced mushrooms on a baking sheet and bake in a very slow oven (as low as your oven will go) for one hour. Turn mushroom slices and bake for another hour. Remove from oven and cool.