Preheat your oven to 400°F (200°C) and line a small baking sheet with parchment paper for easy cleanup.
Trim the woody ends off the asparagus and place them on the baking sheet along with the cherry tomatoes.
Drizzle the vegetables with 1 teaspoon of olive oil and season with a pinch of sea salt and black pepper, tossing to coat evenly.
Roast the vegetables in the oven for 12 to 15 minutes until the asparagus is tender and the tomatoes have slightly collapsed and blistered.
While the vegetables roast, pat the salmon fillet dry with a paper towel and season both sides with the remaining sea salt, black pepper, and garlic powder.
Heat the remaining 1 teaspoon of olive oil in a medium non-stick skillet over medium-high heat.
Place the salmon in the pan skin-side up and sear for 4 minutes until a golden-brown crust forms, then carefully flip the fillet.
Cook for an additional 3 to 4 minutes on the second side until the salmon is opaque and flakes easily with a fork.
During the last 60 seconds of cooking, add the baby spinach directly to the skillet with the salmon, tossing gently until it just begins to wilt.
Arrange the wilted spinach on a plate, top with the seared salmon, and serve with the roasted asparagus and tomatoes and a fresh squeeze of lemon juice.