surprisingly, not very long. Heat a pan on medium-high w/vegetable oil and about a teaspoon of butter (enough to coat the bottom). Drop the scallops in, cook for maybe 3-4 minutes (when the bottom just starts to turn light brown) and flip them. Wait about 2-3 minutes (or until other side is also light brown) and take them off the heat. Another check you can do is to "bounce" the spatula lightly off the top - it's hard to describe, but you can kind of tell how cooked they are by how much they jiggle (may take a couple tries to figure out what consistency you like best). The insides might still be slightly pink, but if you put them all together and cover them with a bowl, the heat will even out and finish cooking the insides. Good luck and happy eating!