Place the garlic flower and egg yolk in a bowl, then whisk to whiten the yolk. Pour in the oil while continuing to whisk. Add the capers, dill, lemon zest and lemon juice, then mix. Set the vinaigrette aside.
Cut the salmon into very small cubes, without chopping too much. Place in a bowl.
Add half the vinaigrette, season and mix. Refrigerate for 15 minutes.
Divide the lettuce between 4 plates, top with a portion of salmon tartar and drizzle with a little of the remaining vinaigrette.