Preheat the oven to 400 degrees F. In a mixing bowl, toss the potatoes with 2 tablespoons of olive oil. Season the potatoes with salt and pepper. Place the potatoes on a baking sheet and roast for 35 to 40 minutes. Remove the potatoes from the oven and cool completely. In a food processor, fitted with a metal blade, add the egg, juice from one lemon, mustard, garlic, and green onions. Puree until smooth. Season the mixture with salt and pepper. With the machine running, slowly add the remaining olive oil until all of the oil is used and the mixture is thick. Reseason the mayonnaise with salt and pepper. In a large mixing bowl, toss the potatoes with the bacon, red onions, sliced eggs, parsley and dill. Season the mixture with salt and pepper. Stir in the mayonnaise and the remaining lemon juice. Mix thoroughly. Cover the bowl with plastic wrap and refrigerate for at least 1 hour.
Consumption of raw or undercooked eggs, shellfish and meat may increase the risk of foodborne illness.