First, prepare the tomato sauce. Heat the oil in a frying-pan over a medium heat and sweat the garlic for a few minutes until soft and starting to caramelize. Add the tomatoes, half of the basil and a pinch of sugar. Season with salt and the oregano. Simmer over a gentle heat for at least 20 minutes. After 15 minutes has passed, cook the bucatini in plenty of salted boiling water until al dente and drain, reserving a little of the cooking liquid. Meanwhile, blanch the courgettes in boiling water for 30 seconds; drain. Sauté the zucchini in half the butter in a heavy frying pan over a medium heat for a few minutes. Season with salt and black pepper. Melt the remaining butter. Arrange the pasta in a three-section rectangular serving dish as follows. In the left-hand section, put one-third of the pasta mixed with a generous amount of hot tomato sauce – keep it warm on the stove until you need it. In the middle section, put another third mixed with the melted butter and lots of freshly grated Parmesan. In the right-hand section, put the last third of pasta mixed with the sautéed zucchini.