Cook the rice and lentils: If you haven't already, prepare the brown rice and lentils according to package instructions. You can cook them both in the same pot to save time.
Prepare the vegetables: Wash and chop the vegetables into bite-sized pieces.
Make the sauce: In a small bowl, whisk together soy sauce, rice vinegar, sesame oil, sugar, sriracha, chili flakes (if using), salt, and pepper.
Sauté aromatics: Heat oil in a large pan or wok over medium-high heat. Add the garlic and ginger and cook for 30 seconds, until fragrant.
Stir-fry the onion and vegetables: Add the onion and scallions. Cook for 3-4 minutes, until softened. Then, add the remaining vegetables and cook for another 5-7 minutes, until crisp-tender.
Add rice and lentils: Push the vegetables to the side of the pan and add the cooked rice and lentils. Stir-fry them for 1-2 minutes to warm through.
Incorporate the sauce: Add the prepared sauce to the pan and toss everything together to coat evenly. Cook for another 2-3 minutes until the sauce is heated through. Taste the stir-fry and adjust the seasonings.
Serve: Transfer the stir-fry to plates and top with garnishes. Enjoy!
