In a large skillet, toast the coconut over medium heat, until golden and crisp; set aside.
Brown ground beef and garlic in the same skillet; drain well.
Add salt, pepper lemon juice and soy sauce.
In a small bowl combine the cornstarch with reserved pineapple and mandarin orange liquids; stir well until smooth then add to ground beef and cook over medium heat for 5 mins, stirring constantly, until mixture is thickened.
Stir in the pineapple and mandarin oranges; cook 2-3 mins, or until thoroughly heated.
Serve over noodles or rice, and sprinkle with more toasted coconut and cashew nuts.