Combine the cabbage, scallion, and jalapeno, if using, in a medium bowl.
Cut the fish into strips. Combine the fish with the lime zest and juice, pimenton, garlic, oil and salt, to taste, in a medium bowl. This can be done a day ahead, covered and refrigerated.
In a small bowl, combine the vinegar, honey and oil. Add to the cabbage mixture and toss until well dressed. Season with salt, to taste. If using within a couple of hours let it sit at room temperature, if making this ahead, refrigerate until ready to use.
To cook and assemble:
Preheat the oven to 350 degrees F. Wrap the tortillas in foil.
Put the fish strips on a parchment-lined baking sheet. Put the fish and tortillas in the preheated oven for 8 to 10 minutes.
While the fish is in the oven, taste the cabbage for seasoning and adjust, if needed.
Remove the fish and tortillas from the oven. Put some fish in the center of a tortilla, top with a couple of avocado slices and finish with some of the cabbage slaw. Repeat with remaining ingredients and serve.