Heat the oil in a heavy-bottomed skillet and fry onions over medium high heat until beginning to soften, about 2 minutes. Add garlic and sweet potatoes, season to taste with salt and pepper, and cook 10 to 15 minutes, until potatoes are cooked through and crispy. Some folks stir the potatoes as they cook to keep them loose and separate, while others allow them to form a cake, which they flip halfway through cooking to ensure even browning. Both ways are good. From www.care2.com.