Preheat oven to 325° F and place the rack in the middle position. Boil 2 quarts of water in a kettle. Grease the insides of the muffin liners with oil and arrange them on a rimmed baking pan.

Squeeze excess water out of the spinach and put it in a food processor or blender along with the eggs, egg whites, cheese, baking powder, salt and pepper.

Pulse until mixture is an even green color with bits of spinach, about 30 seconds. Fill the muffin liners almost to the tops with the egg mixture.

Place the baking pan on the middle oven rack and carefully pour the boiled water into the pan. Bake until firm in the centers, about 20-25 minutes.

Place the potatoes in a microwave-safe dish, cover with plastic wrap and microwave at HIGH for 5 minutes. Uncover and cool slightly.

Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray and add onions; sauté for 3 minutes or until translucent.

Add ham and bell pepper; cook until ham is browned, about 3 minutes. Transfer the ham mixture to a bowl and set aside.

Wipe the skillet clean and return heat to medium-high. Add olive oil, swirl to coat and add potatoes, cut-side down. Cook for 4 minutes without stirring.

Turn potatoes over. Cook for 6 minutes without stirring. Reduce heat to medium-low and stir in ham mixture until warmed up, about 2 minutes.

Transfer muffin liners to a cooling rack to set for 5 minutes.

Serve two muffins with a cup of home fries.