A 750ml terrine takes 650g tomato confit for which 8kg Roma tomatoes is required. By the time they have been cored, de-seeded, confited, skinned, hung and squeezed they will have reduced by 85 - 90% in weight, which gives the confit a very intense flavour. The tomato confit, gazpacho and basil oil can all be made 24 hours in advance. Once the terrine is made, allow it to set for at least 6 hours but preferably overnight in the fridge before turning out and slicing.
Prepare the gazpacho: Roughly chop the tomatoes, cucumber, red capsicum, garlic, Spanish onion and basil. Place the ingredients into a food processor and blend until it becomes a smooth puree. Pass the puree through a fine chinois, pressing hard on the vegetables to extract as much flavour as possible. Discard the pulp. Add the sherry vinegar and Tabasco to taste, taking care not to make it too spicy which will overpower the finished dish. Season to taste with salt and freshly ground pepper. Cover the gazpacho with cling-film and refrigerate until ready to use.
Remove the tomato confit from the muslin cloth. It should be quite dry by now but if it still feels wet, gently squeeze it before untying the muslin. Place the tomato in a bowl and add 25ml extra virgin olive oil, julienne of parsley and basil and stir through the tomato confit. Add the balsamic vinegar and basil oil. Season to taste with salt and freshly ground pepper.
Place the gelatine leaves in lukewarm water for 1 minute to soften. Lift out and squeeze dry. Warm the 50ml tomato water over a gentle heat and add the gelatine, stirring until dissolved. Remove from the heat and allow to cool slightly before stirring into the gazpacho.
Square the 4 quartered tomatoes by trimming all 4 sides with a sharp knife, and lightly season with salt and freshly ground pepper. Line a 750ml terrine mould with cling-wrap with a 1 inch over-hang. Pour a thin layer of gazpacho to cover the base of the terrine and refrigerate for 3 minutes until the gelatine begins to set. Add a layer of tomato confit and smooth out with a palette knife. Pour another thin layer of gazpacho over the tomato confit. Press the squared tomato quarters gently into the gazpacho and refrigerate again for a further 3 minutes or until the gazpacho begins to set. Add another layer of tomato confit and continue to layer the terrine until the terrine mould is full, finishing with a final layer of tomato confit. Fold over the cling-film to enclose the terrine. If the gazpacho begins to set while you are building the terrine, simply place over a very low heat to melt again.
To press the terrine, cut out a piece of cardboard the same size as the terrine and cover first with aluminium foil followed by cling-film. Place on top of the terrine and place a 500g weight on top of the terrine. Refrigerate for 6 hours to set or, preferably overnight.
To serve, remove the weights from the terrine, remove the cardboard and open the cling-film covering the top of the terrine. Run the tip of a sharp knife around the edge of the terrine mould. Invert the terrine onto the cut-out cardboard. Cut a 2cm thick slice of terrine and brush the surface with extra virgin olive oil and place in the centre of a plate. Allow to stand for 15 minutes, allowing it to come to room temperature. Place all the blanched vegetables, cherry tomatoes and sliced olives into a bowl and add the remaining extra virgin olive oil. Season to taste with salt and freshly ground pepper. Spoon the vegetables and sliced olives around the terrine. Drizzle the tomato and basil oils over and around the vegetables and garnish with the picked herbs.