They work great in the oven too!  They definitely taste a bit richer when cooked in the oil and they aren’t quite as crispy in the oven, but in my opinion they are equally delicious when cooked in the oven.   Instructions for oven: To cook in the oven, preheat the oven to 400° F.  Coat your baking tray lightly with baking spray or brush it with oil.  Then place the croquettes on the tray with a bit of space between and place into the oven to cook.  Cook for 10 minutes on one side and then turn to cook 10 minutes on the opposite side.  They should be browned on the top and bottom and be slightly crunchy.