To prepare the Quinoa: Place the quinoa, 1 tablespoon oil and a pinch of salt in a medium pot. Add 2 cups of water. Bring to a boil, reduce heat to low and let simmer for about 15 minutes or until the water has evaporated and quinoa is tender.
Mix the tomatoes, red onion, cilantro and scallions in a bowl. Add the lime juice, remaining 2 tablespoons olive oil, vinegar and salt and pepper. Add the cooked quinoa and mix well.
Place the quinoa salad in a bowl and top with the salmon and avocado slices. Serve immediately.