Add the whole potatoes and whole carrot to a pot of salted water. Bring to the boil and cook for 20–25 minutes, or until very tender

STEP 2

At the same time, boil 2 eggs for 9 minutes. Boil the remaining 2 eggs for 6½ minutes for jammy centres

STEP 3

Transfer all eggs to ice water, then peel once cooled.

STEP 4

In a large bowl, combine the yoghurt, light Kewpie mayonnaise, wholegrain mustard, rice wine vinegar, honey, salt and pepper

STEP 5

Add the 2 hard-boiled eggs, cooked potatoes, cooked carrot, cucumber and spring onion to the dressing. Gently mash everything together until creamy but still slightly chunky

STEP 6

Spread a thin layer of butter over one side of each slice of bread

STEP 7

Divide the potato salad mixture between 2 slices of bread, creating a well in the centre of each. Place a jammy egg into the middle of each sandwich and gently spoon a little extra potato salad around it to hold it in place

STEP 8

Top with the remaining slices of bread and gently press down

STEP 9

Slice each sandwich down the middle to reveal the jammy egg. Sprinkle with roasted sesame seeds and extra spring onion. Serve immediately