For the marinade, place the soy, sugar, olive oil, ginger, garlic and tomato paste into a food processor and blitz to a paste.
Add the water and blitz again until well combined then pour into a frying pan and bring to a simmer.
Add the lemon juice and zest, thyme and chillies and simmer for another 5 minutes until thickened and reduced slightly.
Remove from heat and leave to cool.
Once cooled transfer to a measuring jug so it’s easy to pour and remove the chillies and discard.
For the tuna and pork, place the tuna steaks and pork chops into separate resealable bags.
Pour half of the cooled marinade in with the tuna steaks and the other half in with the pork.
Add the sage leaves to the bag with the pork chops.
Make sure everything is well coated before sealing both bags and placing in the fridge to marinate.
When ready to cook grill the pork chops for 3 to 4 minutes on each side until cooked.
Drizzle the beer over the pork while cooking for an authentic SA braai flavour.
Grill the tuna steaks for a minute a side or longer if you prefer it cooked through.