Preheat the oven to 350 degrees F.
In a large bowl, mix together the pork, veal, beef, grated onion, chopped garlic, 1 tablespoon parsley, cilantro, cumin, chile powder, and 1/4 teaspoon crushed red pepper, 1 tablespoon salt, and the black pepper. Add the egg and combine. Add the bread crumbs and boquerones, if desired and combine. Begin to form meatballs, each about a generous 1/4 cup of the mixture per meatball. Cook's Note: you should have about 20 meatballs. Set aside on a plate.
Heat a 12-inch saute pan over medium high heat. Add 2 tablespoons of the olive oil and add meatballs to the pan. Brown the meatballs on all sides, in batches if necessary and turning gently as needed, until nicely browned, but not fully cooked. Remove from the pan and set aside.
In the same pan, add the remaining 2 tablespoons olive oil, the smashed garlic cloves, and the red onion and toss to combine, cook for 1 minute. Whisk in the flour until it combines with the oil to make a roux and cook for 2 minutes longer. Whisk in the chicken broth, then remaining tablespoon of parsley, the remaining teaspoon of salt, the remaining 1/4 teaspoon crushed red pepper, and the pimenton. Once the liquid comes to a boil it will begin to thicken. Whisk in more broth to reach the desired consistency. It should be the consistency of a thin gravy.
Return the meatballs and their juices to the pan. Baste the meatballs with the sauce and place the pan into the oven. Continue to cook the meatballs, uncovered, for 20 to 25 minutes.
Remove the pan from the oven and transfer the meatballs and sauce to a serving bowl. Garnish with chopped parsley.