6 tablespoons extra-virgin olive oil, more as needed
1 ⅓ c. panko bread crumbs
1 ¼ t. minced thyme
1 large garlic clove, grated on a microplane or minced
1 t. black pepper, more as needed
¼ c. Dijon mustard
2 large eggs
1 ¼ c. all-purpose flour
1 ¼ lb. skinless hake, cod or other white fish fillets, cut into 1-inch-thick strips
1 ½ t. kosher salt, more as needed
1 ½ lb. russet potatoes (about 3 large), cut into 1/4-inch-thick sticks
1. Prepare the fish and chips: Arrange 2 oven racks in the top and bottom third of the oven. Place a large rimmed baking sheet on the lower rack and heat oven to 500 degrees.
2. In a large skillet over medium heat, warm 2 tablespoons oil. Stir in panko, thyme, garlic and 1/2 teaspoon pepper. Cook, stirring frequently, until crumbs are evenly dark golden brown, about 5 minutes. Transfer immediately to a bowl.
3. In a separate bowl, whisk together mustard and eggs. Place flour in a third bowl.
4. Grease an oven-safe wire rack with oil and place it over another rimmed baking sheet. Season fish with 1 teaspoon salt and 1/2 teaspoon pepper. Dredge each piece of fish in the flour, then mustard mixture, then panko mixture, making sure it is well coated with each one before moving to the next. Transfer fish to the wire rack. (You can bread the fish up to 4 hours ahead; store in the refrigerator, uncovered, either on the rack or just on a plate.)
5. In a large bowl, toss together potatoes, the remaining 4 tablespoons oil, 1/2 teaspoon salt and 1/2 teaspoon pepper. Carefully spread potatoes out on the preheated baking sheet and return to oven’s lower rack. Roast until slightly golden and crispy, tossing after 15 minutes.
6. Reduce oven temperature to 425 degrees and transfer the second pan, with the fish still on the wire rack, to oven’s top rack. Bake until fish is flaky and golden and potatoes are well browned and tender, about 10 to 15 minutes more.
7. If wanted salt fish and potatoes immediately after removing from oven. Serve hot, with tartar sauce alongside for dipping.
Salt fish and potatoes immediately after removing from oven. Serve hot, with tartar sauce alongside for dipping.