Put steak and 1/2 cup barbecue sauce into a sealable plastic bag. Turn steak to coat. Marinate in refrigerator for 6 hours.
Preheat grill and begin cooking rice according to package directions.
Halve the zucchini lengthwise, brush with olive oil, season with salt and pepper.
Remove steak from bag, discard the bag and marinade.
Add steak and zucchini to grill. Grill steak to desired doneness. Grill zucchini 2-3 minutes per side, longer if a softer texture is desired. Once steak is fully cooked to your liking, allow to rest 5 minutes and then slice across the grain.
For brown rice salad: Quarter and seed cucumber; slice olives; chop tomato, onion and parsley. Mix these ingredients along with rice and dressing. Serve with steak and zucchini