Bring a pot of salted water to a boil. Cook orzo for al dente texture.
In a large, nonstick saucepan, heat the olive oil on a medium setting. Cook half of onion until tender, about 5 minutes. Combine with rosemary and cooked orzo in a large bowl. Toss well to incorporate, then set aside.
Add garlic and remaining onion to the pan. Cook until soft, about 2 minutes. Add grape tomatoes and Calamata olives. Cook together for about 3 minutes. Remove the skillet from heat, then stir in parsley, and remaining basil. Season with salt and pepper. Set aside.
Rub salmon with salt, pepper and half of the chopped basil. Using the same saucepan from the onions, sauté salmon in the remaining olive oil, until golden on each side. Cook flesh side first, then approximately 5 minutes per side.
Serve salmon atop a small bed of orzo, dazzled with the warm tomato and olive salsa.