Sprinkle chicken with cumin & chili powder. Heat oil in a medium skillet; add chicken & cook over medium heat 3 to 4 min. on each side. Add water & bouillon granules; reduce heat & simmer 15 min. or until chicken is done. Remove chicken from broth, reserving broth in skillet. Cover & chill chicken.
Bring broth to a boil & cook until reduced to 1/4 c. Remove from heat & cool. Strain broth through a sieve & pour into processor. Add avocado, cilantro, lime juice, green onions, pepper & garlic. Process until smooth.
Cook fettucine according to package directions. Drain. Rinse under cold water & drain again. Combine fettucine & half of avocado mixture; toss well. Place in center of a serving platter. Arrange zucchini around fettucine - avocado mixture. Cut chilled chicken into 1/4 in. strips & arrange over fettucine; sprinkle with olives. Spoon remaining avocado mixture into center of chicken; sprinkle with chopped cilantro. Garnish with fresh cilantro leaves if desired.