Get a large saucepan of salted water on to boil. Melt the butter in a large ovenproof saucepan, or Dutch oven, over a low heat, then add the flour and turn the heat up to mediu, stirring all the time, until you get a paste - this is your roux
Add all the sliced garlic - don't worry about the amount, because each slice will caramelize like toffee in the roux. Keep cooking and stirring until golden and the garlic is nice and sticky. Add the bay leaves and slowly whisk in the milk a little at a time to ensure you get a nice smooth sauce. Bring the mixture to a boil, then leave it on a low heat to simmer and tick away, stirring occasionally. Preheat your oven to 425 F
Add the pasta to the pan of boiling salted water and cook following the package instructions. Meanwhile, roughly chop the tomatoes on a board and season them well with salt and pepper. Drain the pasta and add it immediately to the sauce. Give it a good stir and take the pan off the heat. Stir in your grated cheeses, chopped tomatoes, and some of the thyme leaves. A little Worcestershire sauce added now is nice, and so is a little grating or two of nutmeg
Taste it and season it until it's hitting the right spot for you. You want it to be slightly too wet because it will thicken up again in the oven, so add a splash of water if needed
If you've made your sauce in a Dutch oven, leave everything in there; if not, transfer it to a deep earthenware dish. Bake it for 30 minutes in the oven, until golden, bubbling, crispy, and delicious
While it's cooking, put your bread crumbs and remaining thyme into a frying pan with a few drizzle of olive oil over a medium heat. Stir and toss the crumbs around until crunchy and golden all over. Remove from the heat and tip into a nice bowl. Serve your mac and cheese with your bowl of crispy bread crumbs for sprinkling over, and a lovely green salad if you like