Preheat your oven to 400°F and line a large rimmed baking sheet with parchment paper for easy cleanup.
In a medium mixing bowl, combine the ground chicken, one egg, two finely minced garlic cloves, sea salt, and black pepper.
Gently mix the ingredients by hand until just combined, being careful not to overwork the meat which can make the meatballs tough.
Scoop and roll the mixture into 12 small meatballs, approximately 1 inch in diameter, and place them on one side of the prepared baking sheet.
On the other side of the sheet, spread out the cherry tomatoes and the remaining two whole garlic cloves.
Drizzle the olive oil over the tomatoes and garlic, tossing slightly to coat, then ensure everything is spread in a single layer.
Roast in the oven for 18 to 20 minutes, or until the meatballs are cooked through and the tomatoes have just begun to burst.
Remove from the oven and garnish immediately with freshly torn basil leaves before serving.