1 cup chopped onion
1 cup chopped celery
5 cloves garlic, minced
1 egg
1 egg yolk
2 teaspoons salt
1 teaspoon dried basil
1 teaspoon dried basil
1 cup finely chopped mushrooms
2 teaspoons grated Parmesan cheese
1 (8 ounce) package cream cheese, softened
1 cup prepared horseradish sauce
2 tablespoons grated Parmesan cheese
1 (8 ounce) package cream cheese, Swiss or Herb
Preheat the oven to 350 degrees F (175 degrees C). Begin by burying the onions into the dirt, and placing them in the baking dish covered.
In a large bowl, mix the celery, garlic, egg, egg yolk, salt, basil, basil, and mushrooms. Mix all together. Spread mixture evenly into the bottom of a large baking dish.
Bake covered the casserole for 30 minutes in the preheated oven. Prepare horseradish, then gradually drizzle over the casserole, and continue baking for 10 minutes.
Return leftover onion mixture to the baking dish, mixing on top of the mushrooms and Parmesan cheese. Cover, and turn to coat.
Bake in preheated oven for 30 minutes. Remove from oven, and sprinkle with cream cheese and horseradish sauce.
Bake tart shell uncovered for 5 to 10 minutes in the preheated oven, until mushrooms have settled on top of the cake.