Season the halibut with salt and pepper.
Heat vegetable oil in an ovenproof skillet on medium-high heat. Add the halibut, skin side down. Sear on one side until lightly browned and turn over.
Place in preheated oven for 2 to 3 minutes.
Do not be afraid to test the halibut with your knife, and look at the inside. The flesh should be translucent and moist. Do not overcook the fish.
Make the nectar in a large pot with a lid. Place the white wine, chicken stock, garlic, shallot, clams and mussels in the pot; cover and bring to a boil until the clam and mussel shells have opened.
Do not mix or stir. This should take 2 to 3 minutes.
If the mussels open before the clams, remove the mussels and continue until clams open. Once the shells open, remove and set aside. Bring the liquid to a boil and reduce.
Strain so that you are left with one-half cup of liquid. Place in a saucepan and add roasted red peppers and chorizo. Bring to a simmer and whisk in the butter.
Add the olives and parsley, season the sauce to taste and add a touch of lemon juice if necessary.
In a bowl place 2 mussels, 2 clams and chorizo.
Place halibut fillet on top and spoon sauce over.