1) Combine the water and salt in a 1-quart jar which has a tight fitting lid. Add the vinegar, dill, fennel, and rue.

2) Separate the lettuce leaves and add them to the liquid. Seal the jar and let sit until ready (about 48 hours) Note: The original recipe from Columella calls for salting the lettuce first, letting it "sweat" for 24 hours, and then pickling.