Heat oil in an 8-qt. saucepan over medium. Cook onion until slightly caramelized, 8 minutes. Stir in cumin, chile flakes, cinnamon, coriander, garlic, and ginger and cook until fragrant, 1–2 minutes. Add sweet potatoes and stock and bring to a boil. Reduce heat to medium and cook until potatoes are tender, 10 minutes. Add kale and quinoa and cook until quinoa is tender, about 20 minutes. Using a ladle, transfer about 1 cup stock from pan into a bowl, whisk in almond butter, and return to pan. Season with salt and pepper and serve.