Mac 'n' Cheeseburger Croquettes

Add canola oil to a large sauté pan. Sweat onions and garlic for approximately 4 minutes over medium heat until tender and translucent. Add ground beef. Season with 3 teaspoons kosher salt and 1/4 teaspoon fresh ground pepper. Cook beef over medium heat for 5 to 8 minutes, until beef is cooked through, continuously stirring. Once beef is fully cooked, strain out excess fat and moisture with a perforated strainer. Reserve on side. Bring pot of water to a boil and add 1 tablespoon salt. Add elbow macaroni and cook until al dente, roughly 8 to 10 minutes. Drain pasta and reserve. To make the sauce, combine 1/4 cup flour with butter in a saucepot and cook for 5 minutes over medium heat while whisking. Add milk, bring to a simmer (continuing to whisk), and cook over low heat for 10 minutes. Add cheeses and whisk until fully incorporated into sauce. Season with salt and black pepper. Toss pasta and reserved beef in sauce to coat. Heat vegetable oil to 300 degrees F. Roll macaroni and cheese into 3-ounce balls. Dredge in flour, egg wash, and then panko bread crumbs. Fry until golden brown and heated through.