The natural sweetness and creaminess of sweet potato helps to create ramen broth that’s both addictive and nourishing. Soba noodles, made from buckwheat flour (check the label for 100 percent buckwheat flour to make sure they’re gluten-free, if that’s a priority), offer a nutty quality to the dish while mushrooms and the requisite soft-boiled jammy egg give a familiar um ami tang. Greens are required here, for me at least, making this healthy meal-in-a-jar (or container or bowl) look and feel three-dimensional. The just-add-water method means no accidental spills and a lighter lunch to take in your bag.