How to Make It
In a food processor, pulse the baguette pieces until coarse crumbs form. In a medium skillet, toast the crumbs over moderate heat, stirring occasionally, until golden, 8 minutes. Transfer the bread crumbs to a medium bowl.
Wipe out the skillet. Add the bacon and cook over moderate heat, stirring occasionally, until browned and crisp, 8 minutes. Using a slotted spoon, transfer the bacon to paper towels to drain, then stir the bacon into the bread crumbs. Season with salt and pepper.
In a large skillet, heat the olive oil until shimmering. Add the spinach and 3 tablespoons of water and cook over moderately high heat, stirring, until just wilted, about 3 minutes. Using tongs, transfer the spinach to a bowl and season with salt and pepper; keep warm.
Meanwhile, bring a large, deep skillet of water to a simmer over moderate heat. Add the white vinegar and a generous pinch of salt. Crack the eggs into a small bowl, one at a time, and carefully slide into the simmering water. Poach the eggs over moderate heat until the whites are set but the yolks are still slightly runny, about 4 minutes. Transfer the poached eggs to paper towels to drain.
Transfer the spinach to plates. Top with the eggs, a sprinkle of bacon crumbs and a pinch of nutmeg. Serve.
The bacon crumbs can be stored in an airtight container at room temperature for up to 3 days.