1. Prepare the Rice: Cook rice according to package instructions or simmer with coconut milk and water for a creamy coconut rice version. Set aside.
2. Make Teriyaki Sauce: In a small bowl, whisk cornstarch with 2 tablespoons warm water until smooth and set aside. In a saucepan over medium heat, combine soy sauce, water, vinegar, brown sugar, honey (if using), garlic (powder or minced), ground ginger, and sesame seeds (if using). Stir until sugars dissolve, then slowly whisk in the cornstarch slurry. Simmer until sauce thickens slightly, then remove from heat.
3. Cook Turkey and Vegetables: Heat oil in a large skillet over medium-high heat. Sauté diced onion until softened (about 3 minutes), then add garlic and cook until fragrant (1 minute). Add ground turkey, breaking it up with a spatula, cooking until no longer pink (about 7-10 minutes). Stir in broccoli, carrots, bell pepper, and peas (if using), cooking until vegetables are tender, about 5 minutes.
4. Combine and Simmer: Pour teriyaki sauce over the turkey and vegetables. Stir well and simmer for 3-5 minutes to allow flavors to meld and sauce to thicken further.
5. Serve: Divide cooked rice into bowls and top with the teriyaki turkey and vegetable mixture. Garnish with sliced green onions or other toppings like toasted sesame seeds, avocado, or sriracha for extra heat.