In a medium-size skillet, melt 2 tablespoons of but- ter

Add mushrooms

Saute gently until tender

Set aside

In a medium-size bowl, beat together creme fraiche, egg yolks, parmesan cheese, salt, pepper and nutmeg

In a medium-size saucepan, melt remaining butter

Stir in creme fraiche mix- ture

Add peas

Cook over very low heat, stirring, until mixture is heated through and begins to thicken slightly

Stir in cooked mushrooms

Serve over hot pasta at once and garnish with mint, if desired

Serves 4.