1. Put frisée or other greens in large salad bowl. Put olive oil in skillet over medium heat. When hot, add shallot or onion and cook until softened, a minute or two. Add vinegar and mustard to the skillet and bring just to a boil, stirring, then turn off heat.

2. Meanwhile, boil the eggs (~ 7 minutes).

3. RIGHT BEFORE DINNER IS SERVED: if necessary, gently reheat dressing, then pour over greens (they should wilt just a bit), toss and season to taste. Keep eggs on the side