Ground Beef and Potato Picadillo (Ground Beef and Potato Filling) Use as a filling for soft tacos, flour tortilla tacos, enchiladas, chiles rellenos and empanadas. 1 1/2 tablespoons olive oil 1/2 cup onions, minced 1/2 cup potatoes, cut into 1/4-inch pieces and rinsed 1 1/2 pounds very lean ground beef 4 cloves garlic 1 teaspoon Mexican oregano 1/2 teaspoon cumin 1 1/2 teaspoons chile powder 1/2 teaspoon salt, or to taste Heat a skillet over medium heat and add the olive oil, onions and potatoes. Cook the onions until they are soft, but not browned, and add the ground beef in small pieces. Brown the meat, breaking it up as it cooks. Grind together the garlic, oregano and cumin in a molcajete or mortar and pestle and stir it into the meat. Next, add the chile powder and salt. Turn the temperature to very low, cover the skillet, and simmer the filling for 20 minutes, stirring occasionally.