This is the BEST Sweet Potato Black Bean Salad, complete with savory roasted sweet potatoes, black beans, and pickled red onions. The cilantro-lime dressing whips together quickly in the blender and is the perfect complement to the potatoes and beans.
PREP: Preheat the oven to 425 degrees F. (Read Note 1).
SHALLOTS: In a wide-mouth jar, add 2 tbsp red wine vinegar, 1/2 tsp salt, and 1-1/2 tsp sugar. Stir to dissolve sugar. Add in thinly sliced shallots, cover the jar and shake. Let stand at room temperature, shaking occasionally, until the sweet potatoes are done roasting. (Or add all together in a bowl, stirring occasionally.)
SWEETPOTATOES: Wash potatoes and cut in half lengthwise. Cut in half again to get 4 long wedges. Slice the long pieces into 1/4-inch thick pieces and add to an extra-large (15x21-inch) sheet pan. Drizzle on 2 tbsp oil then add all the seasonings. Season to taste with salt & pepper (I add 1 tsp salt & 1/4 tsp pepper). Toss to coat then space out so potatoes have plenty of room (More room = better roast and flavor -- Note 2). Roast 15 minutes, remove, flip, and then roast another 15-20 minutes or until crisp-tender and nicely charred. Remove from the oven and push potatoes to one side of the pan. Dump the drained and rinsed beans on the other side of the pan and let stand for a minute before tossing the two together.
SAUCE: While the potatoes are roasting, work on the sauce. Add everything to a high-powered blender or food processor. Season to taste (I add 1/2 tsp salt & 1/4 tsp pepper). Blend or pulse until you get a nice, smooth sauce. Taste, adjust, and refrigerate until ready to use. (The sauce thickens as it stands, add a splash more of lime juice or water to thin.)
ASSEMBLY: Layer sweet potatoes and black beans on a salad platter. Use a fork to pick up shallots from the jar (leaving the liquid behind) and add on top. Add diced avocado (if using) and then sprinkle the optional chopped pistachios over everything. Drizzle on the sauce to desired preference (using as much or as little as you'd like). Enjoy promptly!
Video
Notes
Note 1: Cashews: If you don't have a high-powered blender or food processor, I'd recommend soaking the cashews first so they will blend nicely. Place cashews in a heat-safe bowl, pour boiling water over and let sit at least 10 minutes. Drain well before using.Note 2: Roasting: Spread the potatoes across the tray, taking care not to overcrowd the pan. The more space the sweet potatoes have (the less crowded they are), the better they roast and the yummier they'll taste. When vegetables are overlapping on a sheet pan, they end up steaming instead of roasting. Additionally, the bigger the pan, the quicker the sweet potatoes will roast!