Hard-boil the eggs: Place the eggs in a single layer in a medium saucepan and cover with cold water by about 2.5 centimetres. Bring to a rolling boil over high heat — you'll see large, vigorous bubbles breaking the surface. Once boiling, cover the pan, remove from heat, and let sit for exactly 12 minutes. The water will still steam gently when you uncover it.

Prepare an ice bath: While the eggs rest, fill a large bowl with cold water and a generous handful of ice cubes. The water should feel properly cold to the touch, not just cool. After 12 minutes, use a slotted spoon to transfer the eggs directly into the ice bath. Leave them for 5 minutes until the shells feel completely cool.

Peel and dice the eggs: Gently tap each egg against the counter to crack the shell all over, then roll it between your palms to loosen. Peel under a thin stream of cold running water — the shell should come away in large pieces, revealing a smooth, perfectly cooked white. Pat the peeled eggs dry with kitchen paper, then dice them into roughly 1-centimetre pieces. You should see firm, bright yellow yolks with no green ring around the edge.

Prepare the celery: Wash the celery sticks thoroughly and pat dry. Trim the leafy tops and the very base, then slice each stick lengthwise into thin strips before cutting crosswise into small dice. The pieces should be about half the size of the egg dice — this ensures every bite has even distribution. You'll hear a satisfying crisp snap as you cut.

Make the dressing: In a large mixing bowl, combine the mayonnaise, Dijon mustard, lemon juice, Greek yogurt, salt, pepper, and paprika. Whisk together until the mixture is smooth and pale yellow with a thick, spoon-coating consistency. Taste a tiny bit — the lemon should brighten the richness of the mayonnaise without being sour.

Combine everything: Add the diced eggs and chopped celery to the bowl with the dressing. Add the chopped chives or spring onion tops. Using a rubber spatula, fold gently but thoroughly, scraping the bottom of the bowl to incorporate all the dressing. Fold until every piece of egg is coated and the celery is evenly distributed — you'll see the creamy dressing clinging to each piece, with flecks of green throughout.

Rest and serve: Cover the bowl with cling film and refrigerate for at least 30 minutes before serving. This resting time allows the flavours to meld and the texture to settle. When you uncover it, the salad should look glossy and smell of fresh herbs and mustard. Serve with extra celery sticks for dipping, or spoon into wraps for a portable lunch.