Looking for a healthier alternative to tuna mayo sandwich? Give this filling a try. It’s full of flavour thanks to the DYC Apple Cider Vinegar – you wont feel like you are missing out. Healthy Tuna SandwichJune 18, 2017 in Meat tagged apple cider vinegar recipe / clever living / DYC tuna / healthy lunch / healthy sandwich filling / sandwich fillings / tuna mayo / tuna sandwich by Susan