To make the salad
Preheat oven to 450°F. Arrange pancetta in a single layer on a baking sheet and bake until browned and crisp, 10 to 12 minutes; set aside to cool.
In an 8-inch sauté pan at least 2 inches deep over high heat, bring water and vinegar to a boil. Reduce to a simmer. Crack one egg into a small cup or bowl. Gently slip egg into skillet, using a slotted spoon to keep white together. Repeat with 3 more eggs, cooking each for about 3 minutes. Gently transfer cooked eggs to a bowl of warm water.
Arrange Live Gourmet Living Butter Lettuce on 4 plates. Top with tomatoes, dividing evenly. Arrange 5 slices crisped pancetta on each salad. Use a slotted spoon to top each salad with an egg. Drizzle with Hollandaise Dressing, sprinkle with pepper, and serve.
Serves 4 as an entree.
To make the Hollandaise Dressing
Combine yolks, 2 tablespoons of lemon juice, and mustard in the top of the double boiler or a medium bowl placed over the pot of water.
In a very slow, steady stream, whisk in butter. Continue to whisk until sauce reaches 140°F. Adjust heat and/or remove from heat to maintain this temperature and cook, whisking constantly, for 3 minutes.
Remove from heat and stir in remaining 2 tablespoons lemon juice, olive oil, salt, and pepper.
Makes about 1 1/4 cups.