1. Prepare pulled lamb: Preheat oven to 325 degrees Fahrenheit (160 degrees Celsius).
2. Place lamb cubes into a shallow baking dish. Add onion, salt, paprika, rosemary, and water. Cover tightly. Bake for about three hours, until lamb is fork-tender.
3. While still warm, use two forks to pull lamb into shreds. Mix together meat, onion, and any pan juices.
4. Meanwhile, prepare the aioli and pickled vegetables.
5. For the aioli: In the bowl of a food processor fitted with the S blade, combine herbs, garlic, and shallot. Process until fine. Add red wine vinegar and salt. Then, while the machine is running, slowly drizzle in the olive oil until mixture is combined and creamy.
6. For the quick-pickled radishes: Combine the vinegar, water, maple syrup or honey, and salt in a mason jar. Add the sliced radishes and allow to sit for 30 minutes.
7. To assemble: On each slice of baguette, spread some aioli, then add some meat and top with pickled radish.