To prepare the sauce, preheat broiler and line one or two baking sheets with foil. Place peppers cut side down and garlic cloves on prepared pans and coat with olive oil. Broil, removing the garlic cloves once softened (5 to 10 minutes), until pepper skins are blackened (15 to 20 minutes). Remove and tightly cover the peppers with foil and let rest until cool enough to handle, about 10 minutes. Remove and discard charred pepper skins and peel the garlic. Place peppers and garlic in a blender along with the other sauce ingredients and puree until smooth. Taste and adjust seasonings to your liking, adding a little ground cayenne if you’d like it spicier. Set aside.
To make the meatballs, combine all the ingredients except the 1 cup of chicken broth in a large bowl and gently combine. Transfer bowl to freezer for about 15 minutes to make mixture easier to roll. Heat a thin layer of olive oil in a large pan (such as a Dutch oven or frying pan) over medium-high heat.
Roll the turkey mixture into balls 1 to 1½ inches in diameter. Place as many as will fit in a single layer in the hot oil, and fry, turning to brown on at least two sides. Remove with a slotted spoon to a plate. Repeat with remaining turkey mixture.
To the empty pan, add the 1 cup of chicken broth and stir about 1 minute to deglaze the pan. Stir in the red pepper sauce until combined, then add the meatballs and any juices to the pan. Stir gently to coat, then cover pan and simmer for 20 to 25 minutes (meatballs should register at least 165 on an instant-read thermometer). Serve hot.