01 - Preheat oven to 400°F. Line a baking sheet with parchment paper and lightly oil or spray it.
02 - Cut fish fillets into 1-inch bite-sized cubes.
03 - Whisk lemon juice, olive oil, Dijon mustard, salt, and pepper in a bowl. Add fish cubes and toss gently to coat. Allow to marinate for 10 minutes.
04 - In a shallow dish, combine panko breadcrumbs, grated Parmesan, sweet paprika, and dried parsley.
05 - Remove fish from marinade, letting excess drip off. Roll each cube in breadcrumb mixture, pressing lightly to adhere.
06 - Place coated fish bites evenly on prepared baking sheet.
07 - Lightly spray or drizzle olive oil over fish bites to enhance crispiness.
08 - Bake for 16 to 18 minutes, turning once halfway through, until golden and cooked through.
09 - Serve immediately with lemon wedges or preferred dipping sauce.