1.Combine beef, garlic, paste, onion, chilli, parsley, breadcrumbs and egg in large bowl; shape mixture into four patties.
2.Combine yoghurt and hummus in small bowl.
3.Cut eggplant into 6 slices lengthways; discard 2 skin-side pieces.
4.Cook patties and eggplant, in batches, on heated oiled grill plate (or grill or barbecue) until browned both sides and cooked through.
5.Preheat grill (broiler). Halve bread pieces horizontally; toast, cut-sides up. Spread cut-sides with yoghurt mixture; sandwich rocket, eggplant and patties between toast pieces.
To freeze: complete recipe to the end of step 1. Individually wrap patties in plastic wrap. Label, date and freeze for up to 3 months. Thaw overnight in the refrigerator. Continue from step 2.