Toast all spices (first 10 ingredients) together by placing them over high heat on the stove in a small heavy skillet. Toss them frequently until fragrant, about two to four minutes. Let cool. Grind all spices. Coat salmon in spices.
In a large, nonstick, hot skillet, brown salmon and mushrooms on high heat for about 3 minutes. Flip salmon, cover, turn heat to low, and cook until done, about 5 minutes depending on thickness of salmon.
Add arugula and balsamic vinegar. Cover and cook on low heat for 2 minutes more.