The main trick with cooking kangaroo meat is to bring the fillet to room temperature before cooking, then you sear it quickly on high heat; 3 - 5 minutes each side, and let it rest a few minutes before slicing or serving.
This technique is to ensure it cooks evenly through the quick searing, and to avoid the meat being over cooked and tough, as kangaroo can tend to be if cooked too long.
I like the idea of making a thai dressing to pour over once the meat is resting, then slice it up and serve on top of a thai salad -
Dressing - 1 tbsp each of rice wine vinegar, lime juice, fish sauce, chilli, garlic, some spring onions- add ginger if you like, lemongrass, peanuts etc or sesame oil..
taste as you go and choose the flavours you like.
Salad- mixed greens, cucumber, fresh herbs like coriander, mint, anything you like - add capsicum, fennel, radish etc..

Hope that helps!

Another favourite way is to serve it with roasted beetroot and green beans.