Prepare the Oven: Place oven rack in the upper middle position. Heat oven to 450 degrees Fahrenheit.
Prepare the Meatballs: To a food processor add in the bread, milk, and egg yolk and process until smooth.
In a large bowl, mix the ground pork, mint, garlic, salt, cumin, oregano, and the bread mixture until well incorporated.
Gently mix in the ground beef until just combined.
Using a 1-tablespoon measuring spoon, form the mixture into meatballs. Place them on a rimmed baking sheet. Make sure to leave some space between each meatball.
Bake for 15-20 minutes, rotating the sheets halfway through, until the meatballs are cooked through and slightly browned.
Prepare the Sauce: While the meatballs are cooking, to a blender, add in the tomatoes, onion, garlic, oregano, cumin, chile chipotle, water, sugar, vinegar, and salt. Process until smooth.
To a 12 inch pan over medium-high heat, add in the oil and wait until warm. Add the blended sauce to the pan, bring it to a boil, then reduce the heat to medium-low and simmer for 10-12 minutes until thickened. Adjust salt to taste if necessary.
Combine Meatballs and Sauce: Once the meatballs are cooked, add them to the pan with the sauce. Cook for an additional 2 minutes to ensure the meatballs are coated and heated through.
Serve: Transfer the meatballs with the sauce to a serving platter. Sprinkle with chopped cilantro.Use toothpicks to skewer the meatballs for easy serving.