Preheat oven to 400°; place 2 large pieces of foil on a sheet pan + oil the foil; divide cod to foil, top each with ½ of butter round + salt/pep; fold empty side of foil over ingredients; working from one end, tightly fold edges of foil creating a sealed half-moon shape; repeat with other foil

Bake 12-15 min until trout is firm, opaque + cooked through

Add asparagus to a sheet pan; drizzle with 1 tbsp oil + season with salt/pep; roast asparagus 9-12 min until tender

Open foil packs by cutting a slit through center (watch out for steam!); divide fish + asparagus between plates then drizzle vinaigrette onto veggies-Woah, that looks so good!