Combine beef, 1 tbs oil and 1 crushed garlic clove in a bowl. Cover and refrigerate for 10 mins to marinate.
Heat a wok over high heat and add 2 tsp oil. Cook the beef in batches until browned and remove to a plate. Add remaining oil to wok. Add onion and stir-fry for 1 minute or until soft.
Crush remaining garlic and add to wok. Stir-fry for 30 seconds. Add asparagus, capsicum and corn. Stir-fry for 1 minute. Return beef to the wok with cashews, kecap manis and sesame oil. Stir-fry 1 minute or until heated through. Serve over rice.