• Place rack in middle of oven and preheat to 425°.
• Place lemon zest, chorizo, Parmesan, fennel seeds, parsley, and garlic cloves in the food processor. Process until chorizo is finely chopped (chorizo pieces should be no bigger than a pea). Transfer chorizo mixture to a medium sized bowl. Add Panko crumbs and 1 tablespoon extra-virgin olive oil and mix by hand until all ingredients are combined.
• Pat fish fillet(s) dry and place in center of a parchment or foil lined baking sheet. Spread a thin layer of mayonnaise over fish. Scatter Panko chorizo breadcrumb mixture on top and pat gently to adhere to the fillet(s) - no need to worry about coating the sides).
• Separately toss baby potatoes with freshly ground pepper, remaining 2 tablespoons extra-virgin olive oil, and kosher salt in a large bowl and then place potatoes on the sheet pan with the fish, pushing the potatoes to edges.
• Roast fish and potatoes until breadcrumbs are golden brown and potatoes are fork-tender, 18–20 minutes. Depending on how big the potatoes are, you may need to remove the fish from the sheet pan and cook the potatoes an additional 5 minutes or so. I like to smash the potatoes with the bottom of a cup but that's optional.
• Serve fish and potatoes straight from the pan or place on a large platter. Top fish with parsley and season potatoes with additional olive oil, kosher salt and pepper, if needed. Serve with aioli, if making.

Optional Aioli

• The potatoes and fish would pair nicely with an aioli. While the fish and potatoes are cooking...combine mayo, , garlic, and lemon juice. Season with salt. Mix until combined and serve with the fish and potatoes.