Gluten Free Matza Poultry Stuffing

Name: Gluten Free Matza Poultry Stuffing
Ingredients: 1 large onion, diced (around 2 cups); 2 stalks celery, sliced (around 1 cup); 2 large carrots, diced (around 1 cup); 1 clove garlic, minced; 1 tablespoon Gefen Olive Oil; 1/2 pound mushrooms, thinly sliced; 1 large egg, lightly beaten; 1 (10- and- 1/2-oz.) box Yehuda Gluten Free Matzoh-Style Squares; 1/2 cup Manischewitz Chicken Broth or other chicken or vegetable stock (or 1 teaspoon consommé mixed with 1/2 cup water); 1/4 teaspoon black pepper