In a medium sized pot, boil the pad thai noodles according to the package instructions. Drain and rinse.
Heat a large wok or saucepan over high heat. Add ? cup of water and the frozen vegetables. Heat for 2 minutes.
Add the chopped bok choy to the pan and continue cooking on high heat for another 2-3 minutes until the vegetables are crisp and tender, adding more water if necessary.
Reduce heat to medium high and add the peanut sauce, coconut milk and sriracha to the pan. Stir to combine and continue stirring for a minute or so until the sauce is heated through. Add the peanut noodles and stir until well covered with the sauce. Season with salt to taste.
Serve garnished with chopped peanuts, chopped cilantro and bean sprouts if desired.