Step 1

Pre-heat the oven to 350*F/180*C/ gas mark Butter a shallow 7-inch square casserole dish. Set aside.

Step 2

Cook the macaroni, according to package directions just until al dente. Drain well.

Step 3

While the macaroni is cooking whisk the cheeses, sour cream, milk, egg and Cajun seasoning together in a bowl. Stir in the cooked macaroni, folding everything together well to combine.

Step 4

Pour into the prepared baking dish. Cover tightly with aluminum foil.

Step 5

Bake for half an hour. Uncover and bake for 15 to 20 minutes longer, until bubbly and golden brown. Serve hot.