In a large skillet over medium-high heat, saute salmon, garlic and onion until salmon starts to become opaque, in the oil for about 2 minutes; remove salmon from skillet and keep warm.
Add remaining ingredients to skillet, reduce heat and simmer gently, covered, for 12 to 15 minutes.
Taste for seasoning, adding salt and black pepper if desired; return salmon to the skillet and simmer for another minute; serve with sauce ladled over the top.