Sieve the flour into a bowl. In a separate pot add the butter, water, olive oil and salt. Place somewhere warm and heat until 37C. Add the yeast.
Pour the wet mixture into the flour and knead with your hands until it forms a firm dough. Cling-film the bowl and leave to prove for 2 hours. Once proved, roll out the dough into a sheet 2mm thick and 30cm long.
Mix the egg yolk with the black olive tapenade and brush over the dough. Cut the dough into your desired shapes. Place on baking tray and bake at 170C/Gas Mark 3 for 5 minutes.
For each dish slice the tomatoes and toss with the olive oil and a sprinkling of sea salt and balsamic vinegar. Warm briefly under the grill at a low setting. Cut the basil into strips and place over the tomatoes along with the borage. To finish, place the grissini on the tomatoes.
