Grease a 34 x 24 x 6cm oven proof dish (tester used a slice pan)
In a large fry pan, heat the oil over a medium high heat. Fry the beef in two batches. Once brown, add the taco seasoning and 1/2 cup water. Simmer until thickened, about 10 minutes. Stir in 3/4 cup enchilada sauce, cook 2 minutes. Take off the heat
Meanwhile, in a medium bowl, combine the ricotta, parmesan and sour cream
Place 1/2 cup of the meat on the bottom of the prepared dish, sprinkle with 1/3 cup ricotta, then layer chips over the top, then sprinkle 1/4 cup tasty cheese. Repeat layers, finishing with chips. Pour the remaining enchilada sauce on top, then extra cheese and bake for 20 minutes or until melted and golden
Tips & Hints:
You can make and freeze the beef mixture up to three months in advance. Defrost the mixture in the fridge the day before eating, then you can construct your Nachosagne quickly and easily!