Place beef on a plate and allow to come to room temperature while you prepare the garlic paste. Place garlic and salt in a mortar and pestle and grind to a fine paste, add oil and stir to combine. Spread beef with a little garlic paste on both sides.
Preheat a char grill over high heat and cook beef for 4-5 minutes per side, depending on thickness, for medium-medium rare. Allow to rest, slice to serve.
Place vegetables in a large bowl with remaining garlic paste, thyme sprigs and leaves. Cook vegetables on the same grill while the beef is resting, turning regularly until golden with some grill marks.
Serve sliced beef with char grilled vegetables and extra sprigs of thyme.
Use 2-3cm thick beef rump if you can't get beef rump cap.
You can marinate the beef and vegetables with garlic paste fin the fridge for up to 24 hours before cooking.