1 1/2 poundswild salmon(one large fillet or four separate fillets is fine)
Preheat oven to 400 degrees F.
Trim Brussels sprouts and cut any larger ones in half (you want all veggies roughly the same size). Peel butternut squash and cut into small cubes, similar to the size of the Brussels sprouts. Mince garlic and place in small bowl with the juice of 1/2 lemon. Thinly slice other 1/2 of lemon.
To the minced garlic and lemon juice, add salt, mustard, maple syrup, thyme, olive oil, and pepper. Whisk to combine. Lightly coat the Brussels sprouts and squash with half of this mixture and place on rimmed baking sheet. Bake for 10-12 minutes.
Coat the fish with the remaining mustard mixture, and cover with lemon slices. When Brussels sprouts and squash are getting soft, add the fish to the sheet tray and bake until fish is cooked through (time will depend on the thickness of the fish).