Prepare the ingredients as instructed above.
Prepare and cook the rice according to the directions on the package. Once tender, season with salt and pepper.
Preheat the grill or grill pan over medium heat.
Season the Tilapia with cumin, cayenne, salt, and black pepper. Drizzle with olive oil.
Grill the fish to an internal temperature of 145°F (63°C). Cut into pieces.
Grill zucchini: Drizzle with oil, salt, and pepper. Grill the zucchini until nicely charred and tender on both sides.
Warm the taco shells on the grill if desired.
Prepare virgin margaritas: Mix all ingredients until combined. Adjust ingredients as needed to taste. Serve over ice, if desired.
Prepare tacos: Fill the taco shells with lettuce, fish, radish, and cilantro.
Serve with lime wedges, brown rice, grilled zucchini, and virgin margaritas.