Put the eggs in a pan, cover with water and bring to a boil over medium heat. Cover the pan, turn off the heat and let stand 10 minutes. Run the eggs under cold water, crack and return to cold water for a few minutes to loosen shells. Chop the eggs and set aside.
Arrange the bread on a baking sheet and toast in the oven until golden, about 8 to 10 minutes. Remove baking sheet from the oven and rub with the garlic. Drizzle with oil and sprinkle with the cheese, then return to the oven to melt the cheese, about 1 to 2 minutes.
While bread toasts, heat a skillet over medium-high heat with 2 tablespoons extra-virgin olive oil, a couple of turns of the pan. Add the pancetta and crisp for about 3 minutes. Stir in the mushrooms and cook until tender, about 8 to 10 minutes. Season with salt and pepper, to taste, and deglaze the pan with Marsala or dry sherry.
While mushrooms cook, combine spinach with red onions and dress with juice of 1 lemon, a liberal drizzle of extra-virgin olive oil and nutmeg.
Arrange the toasts on a platter and top with the mushrooms and spinach. Garnish with chopped eggs and serve.