If you are not into tuna, use a sliced or chopped hard-boiled egg instead. Both options are great sources of protein. We swapped the mayo for a mix of hummus and guacamole for a great heart-healthy mix.
Divide spinach among 4 bowls. Microwave each, uncovered, for 1 minute on high to wilt, if desired.
In a large bowl, gently toss together remaining ingredients, except dill. Divide tuna mixture among bowls with spinach. Sprinkle with dill and serve.