1to make the dressing, add the vinegar, mustard, honey, salt, and pepper to food processor or blender and blend to mix. With motor running, drizzle in the oil slowly at first, then add in a thin, steady stream until all the oil is added. Refrigerate until ready to use.
2To make the salad, preheat the oven to 350°. Spread up the sesame seeds on a baking sheet in a single layer. Toast for about five minutes, or until light brown. Remove and cool.
3Remove the root end of the lettuce and cut the head into four wedges. Place one wedge on each of four individual serving dish. Scatter the mixed greens around each wedge. Top each wedge with cucumber, olives, tomatoes, and feta. Garnish each portion with the dill, toasted sesame seeds, scallions, and onion. Breast each wedge with 2 tablespoons of the dressing and season with salt and pepper. Serves four.