Preheat oven 200. Place serving platter in oven to warm.
Cook spinach according to package directions. Drain well.
Meanwhile heat Alfredo sauce and stir in the lemon juice. Stir in nutmeg and half the sauce into the spinach; keep the remaining sauce warm.
Heat a large nonstick skillet. Cook ham, 1 slice at a time, 30-45 seconds, turning once, until hot and slightly curled.
Remove platter from oven. Place muffin halves, split side up, on platter. Top each with a slice of ham and the spinach, equally divided. Return platter to oven.
Half-fill the skillet with water, add vinegar and bring to a simmer. One at a time break eggs into a small bowl, then slide from bowl into the water. Cover and simmer until whites are set and yolks shake only slightly when the pan is jiggled, 4-5 minutes. With a slotted spoon, gently lift out eggs and place 1 on each muffin half. Spoon remaining sauce over eggs.