1. To make chive salt, combine all ingredients in a medium bowl. Spread mixture onto an oven tray lined with baking paper. Cook in a very slow oven (120C) for about 30 minutes, or until mixture is golden and fragrant. Cool on tray at room temperature.
2. Place corncobs in a large saucepan of boiling water. Simmer for 20 minutes, or until just starting to soften. Drain. Cool for 5 minutes. Cut each cob into three pieces.
3. Before serving, cook corn and tomatoes on
a heated, oiled barbecue. Cook corn for about 10 minutes, brushing occasionally with combined butter and olive oil and turning until browned and tomato slices are slightly softened. When cooked, sprinkle generously with chive salt.