On a microwave-safe plate, cook the onions in the microwave for 2-3 minutes until soft.
Heat oil in a large nonstick pan over medium heat until hot. Add onions and garlic and saute for 2 minutes. Stir in spinach and continue cooking for about 1-2 minutes until spinach is soft. Season with salt and pepper. Remove to a plate and set aside. Set aside the pan for a moment.
In the meantime, break up the matzos slightly and soak in a bowl of cold water for about 1-2 minutes until soft but don’t let them get too soggy! Drain the matzos and squeeze out the water. Combine the matzo in a bowl with eggs and egg whites.
In the same pan, melt the Smart Balance over medium-high heat. Add the matzo/egg mixture, cooked onions, and spinach and scramble, stirring constantly until eggs are cooked.
Divide among 4 plates. Sprinkle each plate with feta cheese and serve immediately. Let everyone season their own with salt and pepper to taste.