In a deep frying pan, heat the vegetable oil over medium-high heat until hot but not smoking. To test if the oil is the right temperature, drop a pinch of flour into the hot oil. If it bubbles up right away it is ready. Adjust heat to keep the oil hot while making the meatballs.
In a separate sauté pan on medium heat, add olive oil, onion, garlic and chili flakes. Cook until onion is translucent, stirring occasionally.
Add serrano, cracked black pepper, adobo, hot sauce to the ground beef. Mix thoroughly to combine.
Add the mixture from the sauté pan to the ground beef and mix again until all ingredients are thoroughly combined.
Using a 1 tablespoon measure, make 1 tablespoon meat balls. Combine the flour and cornstarch. Lightly toss the meatballs in the flour/corn starch mixture.
Fry bolitas in batches, until a golden crust forms. Drain bolitas on paper towels, skewer with toothpicks and serve hot.