Preheat oven to 400°F and line a large baking sheet with parchment paper.
Peel and chop the parsnip, carrot, and rutabaga into 1/2-inch cubes for even roasting.
Toss the root vegetables on the baking sheet with half the avocado oil, minced garlic, sea salt, and black pepper.
Roast the vegetables for 15 minutes until they begin to soften and develop a golden color.
Pat the pike fillet dry with a paper towel and season with the remaining oil, chopped rosemary, and thyme.
Move the vegetables to the sides of the pan and place the pike fillet in the center.
Roast for an additional 10-12 minutes until the fish is opaque and flakes easily with a fork.
Finish with a fresh squeeze of lemon juice over the entire tray before serving.