Peel the hard-boiled eggs and place them on a cutting board. Using a sharp knife, chop the eggs into small, bite-sized pieces. Transfer the chopped eggs to a medium mixing bowl. If you prefer a chunkier egg salad, don't worry about making every piece perfectly uniform.

Using a fork, gently mash the chopped eggs to your desired consistency. For a creamier egg salad, mash the eggs a bit more. If you enjoy extra texture, leave some larger pieces of egg intact for added bite and visual appeal.

Add the plain Greek yogurt and mustard to the bowl with the mashed eggs. The Greek yogurt creates a creamy texture while boosting the protein content, and the mustard adds a subtle tangy flavor that balances the richness of the eggs.

Stir everything together until the ingredients are evenly combined and the mixture becomes smooth and creamy. Be careful not to overmix, as this can make the egg salad too dense. The goal is a well-combined mixture that still has some texture.

Season the egg salad with salt and freshly ground black pepper to taste. Stir once more to distribute the seasonings evenly throughout the mixture. Taste and adjust the seasoning if needed, adding a little more salt, pepper, or mustard according to your preference.

Rinse the romaine lettuce leaves thoroughly under cool running water to remove any dirt or debris. Pat them completely dry with paper towels or a clean kitchen towel. Dry lettuce helps prevent the wraps from becoming watery and keeps them crisp and fresh.

Arrange the prepared romaine lettuce leaves on a serving plate, platter, or clean cutting board. Choose the largest and sturdiest leaves to ensure they hold the filling well without tearing.

Spoon the egg salad mixture evenly into the center of each lettuce leaf, dividing the filling among all four leaves. Spread the mixture gently to ensure each wrap contains a generous amount of the creamy, protein-packed filling.

Fold the sides of the lettuce leaves slightly around the egg salad filling to create easy-to-hold wraps. Alternatively, leave them open-faced and enjoy them as fresh lettuce cups if you prefer a lighter presentation.

Serve the egg salad lettuce wraps immediately for the best flavor and texture. If preparing ahead for meal prep, store the egg salad in an airtight container in the refrigerator and keep the lettuce leaves separate. Assemble the wraps just before serving to maintain the crispness of the lettuce.