1 Tbs. Dijon mustard
1 tsp. minced shallot
2 ½ tsp. kosher salt, plus more, to taste
Freshly ground pepper, to taste
4 Tbs. white vinegar
3 Tbs. extra-virgin olive oil
½ cup diced ham
1 cup halved cherry tomatoes
3 Tbs. fresh basil leaves, torn
4 cups torn butter lettuce leaves
4 egg whites

To make the vinaigrette, in a bowl, whisk together the mustard, shallot, ½ tsp. of the salt, a few grindings of pepper and 2 Tbs. of the vinegar. Let the mixture sit 10 minutes, then whisk in the olive oil.
Warm a sauté pan over medium heat. Add the ham and sauté until ham is cooked to your preference. Transfer to a paper towel-lined plate.
Half fill a wide sauté pan with water and bring to a boil. Reduce the heat to a gentle simmer and stir in the remaining 2 Tbs. vinegar and 2 tsp. salt. Layer 3 paper towels on plate.
Keep the water at a simmer while you toss the salad. In a large bowl, combine the tomatoes, basil, lettuce and ham. Drizzle 2 Tbs. of the vinaigrette over the top, toss to coat and season with salt and pepper. Add more vinaigrette, to taste. Divide the salad among individual plates.
Separate the egg whites, place into bowl. Slide them into the simmering water. Raise the heat briefly to return the water to a simmer but do not allow it to boil. Poach the eggs until the whites are set, about 3 to 4 minutes. Lift the egg whites from the water with a slotted spoon, blot on the paper towels and then carefully place on the salads. Season the eggs with salt and pepper and serve the salads immediately. Serves 4 to 6.