Boil the eggs. Place eggs in a pot, cover with cold water by 1 inch, and bring to a gentle boil. Cover, turn off heat, and let sit for 10–12 minutes. Transfer eggs to an ice bath for 5 minutes, then peel.
Prep the mix-ins. Finely dice celery or pickles, slice green onions or chives, and chop dill if using.
Keep pieces small for even bites.
Make the dressing. In a large bowl, whisk mayo, Greek yogurt, Dijon, lemon juice, salt, and pepper. Taste and adjust acid and salt now, before adding eggs.
Chop the eggs. Roughly chop peeled eggs into small chunks. Aim for bite-size pieces, not a paste.
Combine gently. Fold eggs, celery/pickles, green onions, and dill into the dressing.
If desired, add a pinch of paprika or garlic powder. Mix just until coated.
Adjust texture. Too thick? Stir in another spoonful of yogurt or a splash of lemon juice.
Too loose? Add another chopped egg.
Assemble the cups. Spoon egg salad into lettuce leaves or halved mini bell peppers. Sprinkle with paprika, extra chives, or everything bagel seasoning.
Serve or chill. Enjoy right away, or chill 20–30 minutes for the flavors to meld.
Great with cucumber slices or avocado on the side.