Bring 2–3 liters of salted water (1 teaspoon of salt per liter) to the boil. Clean and wash the cauliflower and cut into small florets. Grate cheese separately. Wash herbs, shake dry, pluck leaves and chop separately. Cook the pasta in boiling salted water according to the instructions on the packet. Cook the cauliflower for the last 5 minutes.
In the meantime, preheat the oven (electric stove: 180 ° C / convection: 160 ° C / gas, see manufacturer). Debark the bread and grind it into large crumbs in the universal chopper. Wash the lemon with hot water, dry it, finely grate the peel. Peel and chop the garlic.
Drain the pasta and cauliflower. Mix with the cream, cheese, except for 3 teaspoons of cheddar cheese, 50 g of diced ham and herbs, except for 2 teaspoons of thyme. Season with salt and pepper. Pour into a baking dish. Sprinkle with the remaining cheddar. Bake in the oven for about 15 minutes.
Heat the butter and oil. Fry bread and 50 g ham in it. Briefly fry the garlic, the rest of the thyme and the lemon zest. Season with pepper. Sprinkle over the casserole.