Stuffed Mushrooms - cooking recipe

Ingredients

12 large cap mushrooms (about 12 oz. total)
4 sticks celery, finely chopped
1 small onion, finely chopped
2 oz. finely chopped walnuts
1/4 c. bread crumbs
4 Tbsp. chopped fresh parsley
2 Tbsp. lemon juice
salt and fresh ground pepper to taste
1 egg, beaten
2 oz. grated Cheddar (optional)
6 Tbsp. chicken stock

Preparation

Wipe mushrooms and pull out the stems.
Chop stems finely. Heat butter in frying pan and lightly brown the rounded sides of mushroom caps a few at a time.
Set aside.