Hoisin sauce: Mince the prunes finely and place them and the rest of the ingredients in a saucepan over medium-high heat. Cook for 6 minutes until thick and richly colored. For a smoother sauce, blend with your immersion blender. Set aside to cool or refrigerate in an air-tight container.

Pickled vegetables: In a mixing bowl, whisk together the ACV and honey. Cut the carrots and daikon into 2 inch matchsticks, or shred them in your food processor with the appropriate blade to get matchsticks. Place the carrots and daikon in the bowl and toss to coat well. Season with salt and pepper to your liking. Cover the bowl and refrigerate until ready to assemble the lettuce cups.

Spicy mayonnaise: In a small mixing bowl, whisk together the mayonnaise and sriracha. Set aside.

Beef and lettuce: Remove and discard the root end of the butter lettuce. Wash, drain, and dry the leaves. Set aside. In a large frying pan over medium-high heat, warm 3 tablespoons of oil until hot but not smoking. Add the beef and cook, stirring occasionally, until browned and heated through, approximately 6 minutes. Remove from the heat and stir in enough hoisin sauce to coat the beef. Season with salt and pepper to taste.

Place the lettuce leaves on one or two large serving platters. Spoon the beef on top of the lettuce. Top that with pickled vegetables. Spoon some mayonnaise over the top. Serve with napkins and enjoy.