over medium heat; cook and stir the onion and garlic in the hot oil until tender, 5 to 7 minutes. stir the oyster sauce into the onion and garlic; season with salt and pepper. add the snow peas, green peas, carrot, celery, and red bell pepper; cook and stir until the vegetables are slightly tender, yet still crisp, 7 to 10 minutes. remove the skillet from the heat.
vegetable mixture and mix well. serve hot. 