Preheat the oven to 425 degrees. Line a rimmed baking sheet with aluminum foil and coat it with a thin layer of olive oil.
Measure out 1/2 the beaten egg and discard it or reserve for another use. In a medium bowl, whisk the ricotta and the remaining egg together until combined.
Put the remaining meatball ingredients in a medium bowl. Mix with your hands or, if you prefer, a wooden spoon. Be careful not to overmix or the meatballs will be tough. Add the egg mixture and stir to combine.
Using about 1 teaspoon of the mixture at a time, form the balls in your hand (you may need to put a little olive oil on your hands to keep the mixture from sticking too much). You want the meatballs to be just ½-inch in diameter. Place them on the prepared baking sheet.
Cook the meatballs in the oven for 10-12 minutes, stirring once or twice, until they are well browned but not hard. Remove from the oven and set aside. Turn the oven down to 375 degrees.