Preheat the oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.

In a large bowl, toss the sliced fennel and cherry tomatoes with 2 tablespoons of olive oil, minced garlic, dried oregano, salt, and pepper until well coated.

Spread the fennel and tomato mixture evenly onto the prepared baking sheet. Roast in the preheated oven for 10 to 12 minutes until the vegetables begin to soften and the tomatoes start to blister.

Remove the baking sheet from the oven and carefully nestle the salmon fillets among the roasted vegetables. Brush the salmon with the remaining 1 tablespoon of olive oil and season lightly with a pinch of extra salt and pepper.

Return to the oven and bake for an additional 12 to 15 minutes, or until the salmon is opaque and flakes easily with a fork (internal temperature of 145°F).

Remove from the oven and squeeze fresh lemon juice over the hot salmon and vegetables. Garnish with chopped fennel fronds and serve immediately with crusty bread or a side of quinoa.