Brown The Beef In Oil For 5 Minutes. Add Vinegar, Water And Salt. Stir Well And Simmer. Prepare A Smooth Sauce With The Onions, Tomatoes, Tomatillos, Garlic, Guajillo Chile, Thyme And Achiote. Add This To The Beef With The Bay Leaves. Continue To Simmer Over Low Heat For 1 Hour. Add Bread Crumbs And Potatos And Simmer For 20 Minutes More. Serve With Rice And Tortillas.