Remove the small green stalks from the tomatoes, cut in half and season with salt.
Grease a baking dish with 1 tablespoon of olive oil, place the tomato halves in with the curvature facing down.
Finely grate the parmesan and half of the pecorino. Use the cheese slicer to scrape off coarse shavings from the second half.
Mix the finely grated cheese with the breadcrumbs and oregano and spread over the tomatoes. Drizzle with 4 tablespoons of olive oil and grill in the oven for approx. 15 minutes until golden brown.
In the meantime, cook the spaghetti and place on a preheated plate.
Pour the gratinated tomatoes and the stock over the drained pasta and sprinkle with the coarsely grated pecorino cheese and the torn basil leaves.
Mix everything carefully, season with freshly ground pepper.
Serve with a fresh rocket salad and oak leaf salad, for example.