Put the flour on a plate. Sprinkle 1 1/2 teaspoon of salt and 1/4 teaspoon pepper on the beef and mix well. Shape the beef into small, firm balls about 1" in diameter; you'll get 32 to 40. Roll the meatballs in the flour, dusting off the excess.
Line a plate with paper towels. In a wok or frying pan, heat the oil on high until it's hot. Fry the garlic until browned, about 1 minute; remove the garlic and set aside. Add the meatballs (in batches, necessary) and sear them on high heat, stirring and tilting the pan, until they're browned evently and cooked through, about 5 minutes. Using a slotted spoon, transfer the meatballs to the paper-towel lined plate to drain.
If not oil remains in the pan, add another 2 teaspooons and fry the red paste so it realeases its aromas, about 2 minutes, stirring with a wooden spoon to prevent sticking. Add the reserve garlic and the cream of the coconut milk and then stir in the peanut butter. Cook and stir to get a smooth, uniform consistency, about 1 minute. Taste and add fish sauce, sugar or more curry paste to taste; the sauce shouldn't be too sweet.
Return the meatballs to the pan with the sauce and simmer over low heat until they're hot, about 2 minutes. Transfer to a serving dish and garnish with the mint or basil sprinkled on top.