Add Potatoes, Salt, Pepper, Allspice And Bay Leaf To Pot And Cover With Water. Bring To A Boil And Simmer Until Tender. Saute Onion In Oil Until Light Brown. Add Flour And Make A Light Brown Roux. Dilute With A Bit Of Water From The Potatoes. Simmer Until You Obtain A Thick Sauce. Add A Little Sour Cream, Vinegar To Taste And The Potatoes. Stir And Serve.