Place the drained tuna in a mixing bowl, then mash with a fork. Add mayo, sweet pickle relish, lemon zest, Dijon mustard, Kosher salt, and black pepper. Stir until well mixed. You can of course add more mayonnaise if preferred.
Add dried cranberries, chopped shallot, chopped dill, then stir. Taste and adjust seasoning as needed.
Enjoy served in endive leaves, with crackers, or on a sandwich! If serving in a bowl, I like to garnish with additional dill.