Toast two slices of bread in a pan with butter, under the broiler, or in a toaster. Set aside.
Mash 1 fresh avocado in a small bowl with salt, pepper, and lemon juice. Set aside.
Prep and cook scrambled eggs, egg substitute, or tofu scramble as desired. Set aside.
Heat a nonstick pan on medium-high heat. Add peppers and sauté for 1-2 minutes, or until softened and fragrant.
Add mushrooms, onion, soy sauce, and balsamic vinegar and cook for an additional 3-5 minutes, or until vegetables have browned and most liquid has evaporated.
Add spinach and sauté for about 1 minute, or until wilted. Set aside to assemble
.Layer toast with avocado, egg/egg substitute, vegetable sauté, feta cheese, and your favorite hot sauce or crema.