Rump steak simmered in coconut milk with green curry paste, tamarind and Thai basil.
This one's already gluten free as written. Just check the label on your green curry paste and fish sauce, some brands add wheat-based thickeners.
Slice the beef thin and against the grain, that's what keeps it tender in a quick simmer like this. Cutting with the grain will leave you with chewy beef.
Sugar snap peas or mangetout work well here too if you'd rather skip the aubergine altogether.