Preheat the oven to 400°F and toss the asparagus with 0.25 tbsp of olive oil and a pinch of salt on a baking sheet; roast for 10-12 minutes until tender-crisp.
Pat the halibut fillet dry with paper towels and season both sides evenly with sea salt and black pepper.
Heat the remaining 0.5 tbsp of olive oil in a skillet over medium-high heat until shimmering.
Place the halibut in the pan and sear for 4-5 minutes until a golden-brown crust forms, then flip and cook for another 3-4 minutes until opaque.
Remove the fish from the pan and set aside on a plate.
In the same pan, reduce heat to medium and add the ghee, minced shallot, and minced garlic, sautéing for 1 minute until fragrant.
Whisk in the lemon juice and fresh dill, scraping the bottom of the pan to incorporate all the flavor into the sauce.
Plate the halibut over the warm quinoa and roasted asparagus, then drizzle the velvety sauce over the fish before serving.