First make you fire and let it die down.
In a skillet, cook your ground beef (or roast veggies) over the fire or on a barbecue!
Make layers of lasagna pasta, meat (or veggies), tomato sauce starting with the sauce then the pasta then the meat and sauce and pasta again until the last layer of pasta.
Cover with whipping cream or béchamel sauce.
Top with cheese then bake.
Once the fire is completely out, place a few stone or a grill grate on the hot coals. Place your dutch oven on top.
Grab some hot coals or hot stones and place them on the lid of the dutch oven.
Bake until the pastas are cooked through and the cheese is melted.