For the pesto, toast the roughly chopped macadamias in a frypan over low-medium heat, stirring every now and then so they don’t burn, until lightly golden – about 5 minutes.
Add the toasted macadamias and garlic to the bowl of your food processor and pulse until the macadamias are the size of large breadcrumbs. Add the basil, mint, chilli and half the salt, then pulse until roughly chopped. While still pulsing, add half the olive oil in a slow stream until the mixture begins to form a pesto consistency. Add the tomatoes and pecorino, then add the second half of the olive oil, pulsing just until the tomatoes are roughly chopped and the pesto still has some texture.
Transfer to a large bowl, taste and add the other half of the salt if needed and freshly ground black pepper to taste.
Meanwhile, cook your pasta in plenty of boiling salted water until just al dente. Drain, reserving ½–1 cup of the cooking water.