You will be needing a lid for your skillet. If your skillet doesn't have a lid, you can use a lid from another pot that might fit or if all else fails, just grab a baking sheet and place it over the top of the skillet.
Heat olive oil in a small non-stick skillet over medium heat. Add garlic and cook briefly, just until fragrant. Add spinach leaves and toss, cooking until just wilted. Remove to a plate. Wipe out skillet.
Reduce heat to medium-low. Add parmesan to skillet in an even layer, forming an oval in the middle. Let cook 30 seconds, then crack an egg over one edge of the parmesan, so the egg is half on and half off the parmesan. Cover skillet and cook until egg is just set. Remove lid and allow to cook another 30 seconds or so more. Use a spatula to transfer parmesan/egg to plate with spinach. Serve with a lemon wedge to drizzle over-top and a generous sprinkling of salt and pepper.