Bring about 3 1/2 cups water to a boil in a small saucepan.
Heat a medium stockpot over medium-low heat and add the oil. Saute the onions in the oil, gradually adding 1 cup of the boiling water and stirring frequently, until the onions are soft and golden brown, 15 to 20 minutes. Add the lima beans and cook until beginning to soften, 10 minutes more. Add the sugar, some salt and red pepper flakes and the remaining boiling water. Partially cover the pan and cook until the lima beans are tender, about 40 minutes. Use the back of a wooden spoon to gently mash one-third of the tender beans and combine to make creamy. Serve warm.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Alzina Toups, Alzina's Restaurant, Galliano, Louisiana