Preheat the oven to 250 degrees. Put a kettle of water (about 3 1/2 quarts) on high heat to boil. Meanwhile, melt 1 tablespoon margarine in a 12-inch skillet on low heat. Add onions, and saute over medium-high heat until soft and golden brown, stirring frequently to prevent burning, about 15 minutes. Add mushrooms, and continue cooking until soft, 3 to 4 minutes. Add rosemary, thyme, parsley, salt, and pepper, and stir to combine. Remove from heat, and set aside to cool slightly.
Break eggs into a large bowl, and beat lightly. Add mushroom mixture, stirring well to combine.
Make batter: Break matzos into 1 1/2- to 2-inch pieces directly into a colander, and pour the boiling water over them. Let matzo stand until softened, about 2 to 3 minutes, and add to the mushroom-egg mixture, adjusting the seasoning with salt and pepper, if necessary. Let stand for 5 minutes.
Melt remaining tablespoon margarine in a 10-inch nonstick skillet over medium heat. Pour 1/4 cup of batter into pan to form a 3-inch pancake, lightly pressing with a spatula to make pancake even. Repeat, cooking 3 pancakes per batch. Cook pancakes until nicely browned, about 2 minutes. Turn and cook the other side about 2 minutes more. Transfer to oven to keep warm and repeat process until all the batter is used up, making about 28 pancakes. Serve immediately.