In a large bowl, combine the ground chicken or turkey, egg, tomato paste, olive oil, parsley, garlic, shallot, salt, paprika, chili flakes, and Parmesan.
In a small food processor, pulse the oats until coarsely ground. Add to the bowl. With clean hands, mix the chicken with the other ingredients until loosely combined. You don’t want to overly break up the meat. Form the chicken into 2-inch balls (an ice cream scoop works well for portioning) and roll in your hands until round and smooth. Arrange the balls on a parchment-lined baking sheet and bake in the oven until cooked through and beginning to brown on the bottom, about 20-25 minutes.
Toss the meatballs with your favorite tomato sauce and serve immediately.