Directions
1. Season steak liberally all over with salt and pepper.
2. Preheat a gas or charcoal grill to a high heat.
3. Brush the grill with oil.
4. Alternatively, heat 1 to 2 tablespoons of oil in a large heavy skillet over medium-high heat.
5. Char steak on all sides, about 4 minutes per side for medium rare.
6. Remove and let sit 5 minutes before slicing.
7. Char the lemon halves, cut side down.
8. Whisk together the vinegar, minced shallot and sugar.
9. Let sit for 5 minutes.
10. Whisk in the mustard then slowly whisk in the olive oil until emulsified.
11. Season to taste with salt and pepper.
12. Toss the dressing with the endive then season with the charred lemon.