1. Start by washing the cucumbers thoroughly. Peel them if desired, but I prefer leaving the skin on for added texture and nutrition.
2. Slice the cucumbers into thick rounds, about 1/2 inch each. Use a melon baller or a small spoon to scoop out a little of the center, creating a small well but be careful not to go all the way through.
3. In a medium bowl, combine the drained tuna, mayonnaise, Dijon mustard, and lemon juice. Mix well until the tuna is fully coated.
4. Stir in the chopped dill, red onion, carrot, and capers if using. Season with salt and pepper to taste. Mama Lou always taught me the importance of tasting as you go, a lesson I hold dear.
5. Spoon the tuna mixture onto each cucumber slice, filling the wells generously.
6. Arrange the cucumber bites on a serving platter, garnishing with additional dill if desired.

These Cucumber Bites with Tuna are best served immediately, as the cucumbers retain their crispness. Mama Lou always said that fresh ingredients make the best meals, and this recipe is a testament to that wisdom.