Combine juice of oranges and limes, crushed garlic, mustard, and vinegar in a small bowl. Place steaks in a 1-gallon sealable bag, add marinade, and refrigerate for at least 1 hour or up to 12 hours.
When ready to cook, preheat the grill to medium-high.
Toss asparagus, oil, salt, pepper, and lemon juice in a bowl.
Grill steaks for 6-7 minutes per side, turning once. Grill the asparagus for about 8 minutes.
Serve steak, thinly sliced, over grilled asparagus and rice. Garnish with sliced green onion.