For the celery squash relish, wash the celery stalks and cut into fine strips. Finely chop the leaves. Cut the seeded pumpkin flesh into small cubes. Slit the chili pepper lengthwise, remove the stalk and seeds. Cut into fine strips. Wash the orange with hot water and rub dry. Grate 1 teaspoon of zest, squeeze out the juice. Pluck the thyme leaves from the branches and chop finely.
Heat olive oil in a saucepan and sauté squash cubes and celery briefly. Stir in spices, sugar, celery greens, orange juice and zest, and deglaze with white wine and vinegar.
Simmer the relish over low heat for about 50 minutes until it thickens slightly. Keep stirring. The relish is ready when you drag the handle of a wooden spoon across the bottom of the pot and a trail remains visible.
While still hot, pour the celery squash relish into prepared twist-off jars, drizzle a few drops of alcohol over the top, light and seal tightly. Place on a tea towel with the lid down and let cool.