For the tomatoes: Preheat oven to 450 degrees F. In a medium bowl add the tomatoes, garlic cloves, olive oil and sprinkle with salt, pepper.
In a baking dish, place the tomatoes and garlic cloves, ensuring they are in just 1 layer. Roast for about 30 minutes, add the basil and capers, then stir well. Set aside.
To cook the salmon: Coat the salmon steaks lightly with oil, season with salt and pepper,
Grill fish to medium rare, about 3 minutes per side. (Fish should be well colored on the outside and barely translucent at the center.