Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.
Toss the cubed sweet potatoes with 0.25 tbsp olive oil, half the sea salt, black pepper, and dried oregano.
Spread the sweet potatoes on the baking sheet and roast for 15 minutes.
Add the trimmed green beans to the baking sheet, toss with the remaining seasonings, and roast for an additional 10-12 minutes until tender.
While vegetables roast, season the salmon fillet with the remaining sea salt and pepper.
Heat the remaining 0.25 tbsp olive oil in a non-stick skillet over medium-high heat.
Place salmon in the skillet and sear for 4-5 minutes per side until the exterior is golden and the fish flakes easily with a fork.
Stir the minced garlic into the pan during the last minute of cooking the salmon for aromatic flavor.
Plate the salmon alongside the roasted vegetables and drizzle with fresh lemon juice before serving.