Line 12 square tart pans and a small square pan (or 3 9-inch round pan or 3 loaf pans) with Gefen Parchment Paper and set aside.

Heat oil in a large skillet. Sauté onions over medium heat until brown, approximately 20 minutes. Add mushrooms and continue sautéing for 6–8 minutes, or until mushrooms begin to wilt and shrivel, but don’t brown. Set aside.

Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).

Place grated zucchini in a large strainer and squeeze out very well. Transfer to a large bowl.

Add sautéed onions and mushrooms. Add remaining ingredients, aside from bread crumbs, and mix very well. Taste and adjust seasoning if necessary.

Pour into prepared pans and sprinkle with bread crumbs. For square kugelettes, bake 30 minutes. For round pans or loaf pans, bake 45–60 minutes.