Heat oven to 350℉. Coat 4 individual soufflé dishes (or a 2-quart casserole dish) with 1 tsp. vegetable oil. Make 3-4 slits in sweet potato; cook in microwave until just soft.
When cool enough to handle, peel, cut into chunks, and purée in food processor. Heat remaining vegetable oil in sauce pan, and sauté kale about 5 minutes.
In a medium sauce pan, boil water and milk, add grits and sweet potatoes; cook 5 minutes. Remove from heat; stir in sautéed kale.
Divide grits mixture evenly among 4 soufflé dishes (or place all in casserole dish). Make 4 depressions in the grits mixture with the back of a large spoon in each dish.
Carefully break one egg into each hollow. Bake uncovered for 15 minutes or until eggs are cooked. Let cool 10 minutes before serving.