Cut bacon into lardons (¼ inch crosswise slices). Heat sauté pan over medium heat, Add bacon and cook until evenly browned on all sides, 5-6 minutes.
Remove all but 2 tbsp bacon fat. Add shallots to bacon and cook about 2 minutes until translucent but not browned. Transfer lardons and shallots to a bowl with a slotted spoon. Wipe out skillet with paper towels.
Make vinaigrette by combining vinegar and mustard together in a sealed container and a pinch of salt. Gradually pour in the olive oil. Seal and shake to incorporate. Season with salt and pepper. Shake again right before using.
To poach eggs, fill a deep skillet with water about 1 inch deep. Add white vinegar and bring to a boil and then lower heat to get a gentle simmer. Break each egg into a clean cup and carefully slide 1 egg into simmering water and cook until whites are set, 3-4 minutes. Remove with slotted spoon and blot them with a paper towel and use or refrigerate them in a bowl of cold water until needed. When ready to use out of the refrigerator, reheat in simmering water for about 30 seconds, blot dry, and use.
If using Frisee, separate leaves, rinse in clean water and dry with paper towels. Put salad greens in a bowl and mix in ½ cup vinaigrette. Divide equally between serving bowls.
Heat 1 tbsp of vinaigrette in the sauté pan over medium heat. Add bacon shallot mixture and warm, about 1 minute. Top greens in each serving bowl with warmed bacon mixture, croutons, a poached egg in the middle and a sprinkling of herb mixture, salt and freshly ground black pepper.