Preheat your oven to 180 degrees.

In a large deep pot, boil water for your macaroni. Once it starts to boil, season with salt and olive oil and stir. Add the pasta and boil for 5-7 minutes. Drain the pasta and rinse with cold water to stop the cooking process. Reserve some pasta starch water for later. Don't toss the pasta around, just let it sit while you rinse it. This helps keep some of the starch in place. Drain the cold water and keep the cooled off macaroni aside while you make the cheese sauce.

Fry or bake the bacon. No need to add extra oil. Remove excess oil from bacon using kitchen tissue paper. Chop the bacon into bits and keep aside. In a pan saute the onions till golden, add the chopped garlic and salute till raw smell disappears. To this add the hot chilli sauce and salute for 2 mins and keep aside.

In a pot heat the milk with crushed garlic and thyme sprigs on low heat for the cheese sauce. Do not let it boil. Once heated drain the solids before using it for the cheese sauce. Rinse the pot you boiled the pasta in with cold water to cool it off completely then place back on top of your stove over medium heat. Add the butter to melt. Once it starts to foam/sizzle, it's ready for the flour.

Add 1 cup of the hot milk, and continue to whisk vigorously until smooth, about 20 to 30 seconds. Add remaining 3 cups of milk and continue whisking to prevent flour from depositing at the bottom of the pan. Add the salt, freshly ground black pepper and nutmeg. Mix well. Taste it and adjust the seasoning as you need to.

Add the parmesan and cheddar cheese and stir gently until it's melted and smooth, about a minute or two.  Combine the cooked and cooled off pasta with the cheese sauce. Gently fold together until it's completely coated. Mixture should be slightly loose but very creamy and easy to work with, if it's too thick, thin it out with a little of the starchy pasta water. Fold in the basil at the last minute.

Transfer half of the pasta and cheese mixture to a lightly greased baking dish. Sprinkle ½ cup of the mozzarella cheese, half of the chopped bacon bits and 1/2 the chilli onion mixture over the first half of the pasta/cheese mixture.

Then pour the remaining pasta/cheese mixture on top as a second layer. Add the remaining mozzarella cheese, bacon and onion on top. Gently swirl a spoon or butterknife thru the mac and cheese mixture to ensure the mozzarella cheese is evenly combined throughout the dish.

Bake in the oven on the middle oven rack for 25-35 minutes, or until golden brown on top and bubbly all over.

Allow the dish to cool for about 10 minutes before you dive in (trust me, it's molten-lava hot).

Enjoy.