Whereas the potatoes are roasting, place the spinach in a big, microwave-safe bowl, cowl, and microwave on HIGH till the spinach is wilted however nonetheless vibrant inexperienced, 90 seconds. (Alternatively, you may steam the spinach in a steamer basket set over a pot of boiling water for 90 seconds.) In a medium bowl, stir collectively the peanut butter, water, soy sauce, vinegar, ginger, lime juice, honey and purple pepper flakes till effectively mixed and creamy. Style, and season with extra purple pepper flakes, if desired.