Mix oil and cumin with chicken breasts in a plastic bag. Marinade for at least one hour.
Grill on a grill pan or barbecue. Let rest 5 minutes before slicing.
In a non stick pan over medium high heat add garlic and onion and cook for 3 minutes, add vegetables and cook until slightly charred but still firm. Toss with salsa.
Layer the rice, chicken and vegetables in a bowl or on a plate.