To make the chipotle tartar sauce, combine all of the tartar sauce ingredients in a small bowl and mix well. Adjust the salt to taste. Cover with plastic wrap and refrigerate until ready to use.
To make the fish tacos, rinse the fish under cold running water and pat dry with paper towels. Cut the fish into 1-inch cubes and place in a large bowl. Add the Worcestershire sauce, the garlic, salt, and pepper and turn the fish to coat. Cover with plastic wrap and refrigerate for at least 20 minutes or up to 4 hours.
Place the flour in a shallow dish and toss the fish pieces in it a few at a time, until they’re all evenly coated.
Heat the vegetable oil in a large pot over medium-high heat to 375 F. Carefully add a few pieces of the fish at a time, shaking off any excess flour before placing them in the oil. Fry until the fish pieces are golden brown all over, about 4 to 6 minutes, and transfer to a paper towel-lined plate to drain.
Meanwhile, heat a medium skillet over medium-high heat. Add a tortilla and warm for 10 to 15 seconds. Flip the tortilla over and continue to warm until the tortilla is pliant and heated through, about another for 10 to 20 seconds. Place on a plate, cover with a kitchen towel, and set aside; repeat with the remaining tortillas. Keep warm.
Spread a dollop of the chipotle tartar sauce onto a warmed tortilla. Add a few strips of cucumber and top with 3 or 4 pieces of fish. Cover with a few arugula leaves, cilantro leaves and a sprinkling of orange zest. Serve with more Chipotle Tartar Sauce on the side and lime wedges on the side.