Heat the oven to 200c. Add the tomatoes to a baking dish with the olive oil, thyme, salt and pepper. Roast in the oven for 30-45 minutes until bursting and juicy but keeping their shape.
Then make the pesto: Toast the pistachio nuts in a dry frying pan over medium-high heat until they are a light brown colour. Keep them moving to prevent burning.
Add basil leaves, Parmigiano Reggiano, garlic clove and pistachios to a food processor. Grind until they start to break down into smaller chunks and combine. You should have a creamy yet slightly chunky consistency. Drizzle the olive oil and continue to grind until you have a creamy paste.
Assemble your sandwich. Slice the ciabatta in half and toast in a little oil in a pan until golden.
Spread your pesto on both sides and then on the bottom part of the bread, add your burrata, prosciutto, and then the confit tomatoes. Cover with the other half of the bread and slice. Serve!