For the preserved celery-carrot salad, peel and coarsely grate the celery and carrots. Peel shallots and cut into rings. Mix the celery, onions and carrots in a bowl with 2 tbsp salt and leave to soak for 2 hrs.
Rinse the vegetables under running water and let them drain properly. Add the dill seeds and orange peel and pour everything loosely into the hot sterilized jars.
Bring the water, orange juice, vinegar, sugar, and remaining salt to a boil in an acid-proof saucepan; skim off the foam.
Fill the jars with the broth. Poke the vegetables a few times with a toothpick to release any air bubbles, close the jars tightly.
Allow the preserved celery-carrot salad to infuse for a week.