- Preheat grill or oven to 425 degrees F.
- Prepare 8 (8-inch long) sheets of foil and set aside. Each fajita packet will use 2 pieces of foil.
- Thinly slice the flank steak across the grain.
- In a bowl, add garlic, salt, pepper, thyme, and sliced beef and toss together well.
- Lay out eat double foil packet and add ¼ cup of rice to each.
- Top with the onions and peppers, splitting evenly between the four foil packets.
- In a bowl or measuring cup, whisk together lime juice and water. Pour evenly over each foil packet.
- Tightly seal each packet.
- To cook: Place on the grill for 20 to 25 minutes OR place packets on a sheet pan and place in the oven for 25 minutes.
- Allow to sit for 5 to 10 minutes then open carefully and fluff rice with fork.
- Serve with cilantro, tomato, sour cream, and avocado.
Tightly seal your packets: Packet cooking uses steam to cook the food, so tightly seal each packet so nothing escapes!