Yay, more cheat days!
Not a quick recipe, but easy nevertheless, and totally worth it.
Saute onions and garlic in a little oil before adding minced meat. At this point I like to add a tiny pinch of cumin and paprika (my little touch), but that's optional. Then add tomatoes/tomato sauce, and season with salt, pepper and oregano, and simmer till it thickens.
Make a bechamel sauce. Melt some butter and add some flour. Take off the heat to add milk and put it back on the heat. Add loads of parmesan cheese. Season and thicken.
Check whether your lasagna sheets require pre-cooking or not. Spread some of the meat sauce. Arrange lasagna sheets on them, and then layer with the cheese. Repeat: meat, sheets, cheese. Finish the top layer with a last layer of lasagna sheets and then cheese sauce and finally, freshly grated mozzarella on the top and bake till you see all that cheese bubble and turn golden.
Die from too much cheese.