Heat a grill pan over medium-high heat then coat it with cooking spray. Place the veggies into the grill pan and let them sit for 4-5 minutes before flipping. Cook for another 3-4 minutes then remove from the pan. Let the vegetables cool a bit before dicing them up.
If you use leftover rice, heat the rice in the microwave. Place the rice into a large mixing bowl then add the grilled veggies, sea salt, freshly cracked pepper, and garlic powder, to taste. Toss well then taste; re-season if needed. Serve with a drizzle of soy sauce. Enjoy.