Shape the beef into small balls. Press and roll the balls in the flour dusting off the excess. Heat the oil in a wok until a haze forms and fry the garlic for 1 minute. Add the meatballs and fry until brown. Remove with slotted spoon and drain on paper towels. In the remainder of the oil, fry the curry paste for 2 minutes. Add coconut milk and stir in peanut butter. Continue cooking and stir until smooth. Season with sugar and fish sauce. Return the meatballs to the sauce and simmer over low heat for 5 minutes. Remove and garnish with basil or mint.