Place 4 eggs in a small pot and cover them with cold water. Bring the water to a rolling boil over medium-high heat, then remove from heat, cover the pot with a lid, and let sit for 10 minutes. This gives you perfectly cooked hard boiled eggs every time—I used to overcook them constantly before I figured this out.

After 10 minutes, transfer the eggs to an ice bath (a bowl with cold water and ice cubes). Let them cool for at least 5 minutes so you can handle them without burning your fingers. The ice bath stops the cooking process and makes peeling way easier.

Gently peel each egg under cool running water, starting from the wider end where the air pocket is. Roll them gently on the counter to crack the shell all over before peeling. Don't panic if a little bit sticks—that's completely normal and the egg is still totally fine.

Chop the cooled eggs into chunks (not too fine or they'll get mushy). Add them to a medium bowl with 1/2 cup mayonnaise, 1 tsp Dijon mustard, and 2 tbsp sweet pickle relish. Mix gently with a fork until you reach your preferred consistency—I like mine with some texture, not completely smooth.

Fold in 1/4 cup diced celery, 2 tbsp minced red onion, and 1/4 cup fresh parsley. Season with 1/4 tsp salt and 1/8 tsp black pepper, then taste and adjust as you go. The parsley adds a fresh brightness that people always ask about—don't skip this part because it really makes the egg salad sandwich sing.

Toast your 2 slices of whole wheat bread until they're lightly golden. Spread a thin layer of the egg salad mixture on each slice, then top with lettuce leaves and 1 tbsp shredded cheddar cheese. The warm toast keeps everything from getting soggy while the cheese melts slightly from the heat.

Cut diagonally (this is non-negotiable in my house) and serve immediately. If you need to make this ahead, keep the egg salad filling and bread separate, then assemble right before eating. This egg salad sandwich is best enjoyed fresh when the bread is still slightly warm.