Heat oil in large saucepan or casserole dish; add pancetta and cook until its fat starts to run. Add onions and garlic and cook until translucent. Add beef and cook until brown.
Add tomato paste, thyme, wine, tomatoes and seasoning; bring to a boil. Cover with a cartouche (round of baking paper that sits directly on the meat sauce) and cover with lid. Simmer gently or transfer to preheated oven (150°c) and cook 45 minutes.

Meanwhile, in a heavy based saucepan, melt 50g butter over a medium/low heat. Add flour and Dijon mustard and cook thoroughly, stirring constantly for 2-3 minutes. Reduce heat.

Stirring or whisking constantly, gradually add milk to the roux, making sure all the lumps are stirred or whisked out after each addition. Continue to add milk until you have a smooth thick sauce.

Continue to cook, stirring constantly, until sauce boils and is thick and velvety. Stir in 1 cup of cheddar and season with salt and pepper.

In a 35cm x 25cm oven dish, alternately layer the meat sauce and pasta for 2 layers each. Then add half of the white sauce. Repeat the 2 layers of meat sauce and pasta finishing with pasta.

Top the pasta layer with the remaining white sauce and cheese.

Bake at 160°c fan-forced 40 minutes until bubbling and golden.