Preheat oven to 300°F.

Line baking half-sheet with foil and spray with vegetable oil spray.
In a bowl, sprinkle halibut pieces liberally with salt, pepper and half of the lemon juice, then set aside while preparing the crumbs.

Melt butter in a large skillet over medium heat, add onion and ½ t. sea salt, and cook until translucent.
Add Panko and cook until toasty brown.  
Remove from heat and stir in parsley.

Whisk together mayonnaise, egg yolk, the rest of the lemon juice and zest, and a little salt and pepper. Pat fish dry with a paper towel.
Coat fish pieces with mayonnaise mixture, then place on baking sheet. Press crumbs into tops and sides of fillets, mounding some on top.

Bake fish until centers are solid white but not flaky and dry (or fish registers 135°F on an instant-read thermometer), 30-40 minutes.
Rotate pan halfway through baking. If crumbs don’t look dark enough, broil for a few seconds at the end of cooking.

Notes: With its surprising marinade, this is an old-school Oregon Coast favorite with a twist. Mayo halibut was named over and over again as a home cook favorite in my statewide Oregon Humanities Conversation Project, “Fish Tales: Traditions and Challenges of Seafood in Oregon,” discussions.

Recipe by Jennifer Burns Bright, Local Food Educator and Travel Writer