Makes right around 2 cups, plenty for garnishing 4 pate
1.5sheets leaf gelatin or 2 tsp powdered gelatin
1tbspunsalted butter and 2 tbsp flour
Kosher salt to taste
Rehydrate the morels in the water until soft, at least 10 minutes. Agitate the morels in the water to remove dirt, then remove the mushrooms, strain the liquid, and re-combine.
Melt the butter in a small saucepot, the add the flour and cook, stirring to create a soft roux. Gradually add the dried morels and their liquid, whisking occasionally.
When all the mushrooms have been added, soak the gelatin sheet in tepid water until soft. Add the bloomed gelatin to the cream, then add the mixture to the pan, and whisk to incorporate until heated through.
Puree the mixture in a blender, then pass through a mesh sieve and reserve until needed, placing plastic wrap directly on the surface of the sauce in the refrigerator to prevent it from forming a skin.
You need to make sure that the sauce jells and holds it's shape. If for some reason it is still liquid after thoroughly cooling, add more gelatin, puree, and re-chill until it sets.