Sterilize the jars. For more information on sterilizing jars, have a look at this post.

Wash the green tomatoes. Peel and thickly slice the carrots. Peel the celeriac and cut it into cubes, about the size of the carrot slices. Clean the celeriac leaves as well. Peel the horseradish, wash it thoroughly and cut it into finger-thick stripes, about as thick and long as the little finger.

Bring the water and the salt to a boil. Let boil for 3-4 minutes. Let cool slightly, not longer than 3-4 minutes. If it gets too cool, reheat it.

In the meantime place some of the horseradish stripes on the bottom of the prepared jars. Start adding the green tomatoes, alternating some carrot slices, celeriac cubes, celeriac leaves, more horseradish stripes, garlic cloves and bay leaves in between.

Sprinkle some mustard, dill seeds, and black peppercorns in each jar.

Carefully pour the hot pickling liquid in the jars. Wait for 1 minute to allow the liquid to set in the jar and add more liquid if the tomatoes are not completely covered with pickling liquid. Seal the jars very well.

Process in a boiling water bath or canner for 15 minutes, adjusting for altitude.

Leave the pickles for four weeks before you start eating them. Once you open a jar, keep it in the fridge.

See above for serving ideas.