Trim stems and wash mushrooms thoroughly. Drain and place in a saucepan with cold water, lemon juice and salt, to taste. Bring gently to a boil; lower heat and simmer for 10 minutes. Place blanched mushrooms in a shallow earthenware dish.
Combine the remaining ingredients in an enamelled saucepan; bring to a boil; lower heat and simmer for 20 minutes.
Pour marinade over mushroom