Heat a tablespoon each of grapeseed (or canola) oil and sesame oil in a large sauté pan on high heat. Add the chopped yellow peppers, green onion and garlic(add onions and garlic a min or two after the pepper) and cook, stirring occasionally until lightly browned. (Keep a watch so that the onions and garlic don't burn.).
Lower the heat and add the bok choy. Stir to coat with the oil in the pan. Cook only until the bok choy has wilted. The thicker, whiter ends of the baby bok choy should still be somewhat crunchy. Season as and if desired.