Season chicken breasts as desired with salt, pepper, garlic salt, taco seasoning, etc.
Heat oil in a large nonstick skillet; cook chicken over medium high heat, turning occasionally until browned and meat is cooked through (10 to 15 minutes, depending on thickness of meat). Remove chicken from skillet; cut into 1/2-inch strips; keep warm.
In medium saucepan, bring broth to a boil; stir in couscous. Remove from heat and cover. Let stand 5 minutes.
In the same skillet place zucchini and yellow pepper; cook over medium heat, stirring occasionally, until tender yet crisp, about 5 minutes.
Fluff couscous with a fork and place on large platter. Drizzle with 1/2 of salsa. Top with zucchini and peppers, then chicken. Sprinkle with cheese. Drizzle with remaining salsa.
Top with dollops of sour cream and green onions.