Preheat the oven to 220°C.
Sauté shallots and onions in olive oil in a heavy-based pan for 4 minutes.
Add cubes of carrot and cook for an additional 5 minutes.
Stir in the diced chorizo and cook for 5 minutes until oils release.
Add butter beans and warm through on low heat, adding stock if necessary.
Stir in the chopped parsley and season with salt and pepper.
Score the halibut skin and season the steaks with salt and pepper.
Sear halibut skin-side down in olive oil for 3 minutes, then roast in the oven for 5 minutes.
Flip the fish and roast for 5 more minutes until cooked through.
Serve the halibut on warm plates topped with the bean and chorizo mixture and a lemon wedge.