Please note that almost all of the prep time is refrigeration time.
Combine the orange zest and orange juice with the lime juice in a medium-sized bowl.
When you're ready to serve, add a few baby greens, about 1 1/2 tablespoons or so of the ceviche, and an avocado slice (or two).
These are small tacos -- I like them that way, but you can also us larger tortillas and use more of the ceviche to fill them.
Of course you can also have the ceviche with chips, in a salad, over bread, or simply with a spoon.
If you can't find blood oranges you can use another juicy orange. I love the blood orange flavor and it's just so pretty!