Celery peel, halve and cut the halves into 6 slices each. Season breadcrumbs with curry, salt and pepper. Whisk the eggs and turn the celery slices first in it and then in the breadcrumbs.
Place on a baking tray lined with baking paper and bake in a preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer) for approx. 40 minutes.
Peel the grapefruit so that the white skin is completely removed. Cut out the fillets with a knife. Squeeze out the fruit residues and collect the juice. For the dressing, mix the grapefruit juice with mustard, vinegar and oil.
Clean and wash the lamb's lettuce and shake it well dry. Roast sunflower seeds in a pan without fat. Take out and let cool down. Mix lamb's lettuce, grapefruit fillets and dressing. Arrange everything and sprinkle with sunflower seeds.