Mushroom Potato Puff

• 1/3 cup butter
• 2 tbsp grated Parmesan cheese
• 3 cups sliced crimini or regular mushrooms (8 oz.)
• 1/3 cup all purpose flour
• 11/2 cups warm milk
• 6 eggs, separated
• 1 1/2 cups mashed potatoes
• 1 cup shredded Gouda or Edam cheese
• 2 green onions chopped
• 2 tsp Dijon mustard
• 1 tsp salt
• 1/4 tsp pepper

Grease 10 inch oval glass baking dish with 1 tbsp. of the butter, sprinkle Parmesan cheese over bottom and up side.

In large saucepan, heat 1 tbsp of the remaining butter over medium-high heat; cook sliced mushrooms, stirring occasionally, for about 5 minutes or until no liquid remains. Transfer to large bowl and set aside.

Melt remaining butter in pan over medium heat; add flour and whisk for 1 minute. Whisk in warm milk in slow steady stream and bring to boil; reduce heat and cook for 2 minutes. whisking constantly. Remove from heat./ Whisk in egg yolks, 1 at a time; add to mushrooms in bowl. Stir in mashed potatoes, cheese, onions, mustard, salt and pepper.

In separate bowl, beat egg whites until stiff peaks form. Stir about one quarter into potato mixture; fold in remaining egg whites. Spread in prepared dish.

Bake in lower third of 400o oven for 25 minutes or until puffed and knife inserted in centre comes out clean.

Makes 6 servings