Preheat oven to 400°F and line a baking sheet with parchment paper for easy cleanup.
Peel the sweet potato and cut it into uniform half-inch cubes to ensure even roasting.
Toss the sweet potato cubes on the baking sheet with 0.5 tsp of olive oil and a pinch of sea salt and black pepper.
Roast the sweet potatoes for 10 minutes to begin the caramelization process.
In a small bowl, combine the dried parsley, dried dill, and lemon juice to form a thick, aromatic herb paste.
Remove the baking sheet from the oven, move the potatoes to one side, and place the salmon fillet on the other side.
Spread the herb paste evenly over the top of the salmon and season with the remaining salt and pepper.
Return the pan to the oven and roast for another 12 to 15 minutes until the salmon is opaque and flakes easily with a fork.
While the salmon finishes, heat the remaining 0.5 tsp of olive oil in a skillet over medium heat.
Add the minced garlic and fresh spinach to the skillet and sauté for 2 minutes until the leaves are just wilted.
Plate the herb-crusted salmon alongside the roasted sweet potatoes and garlic spinach for a nutrient-dense, clean meal.