What are the crucial ingredients or cooking techniques to a more solid, or "brick" like lasagna? Most lasagna I've seen tends to get a bit sloppy in the pan as it's being dished out but I have seen lasagna that comes out very firm and solid. Is this due to a certain combination of ingredients, a cooking technique, or both?
For example, I've seen recipes that use cream cheese and eggs instead of ricotta, and various combinations of tomato paste, sauce, and crushed tomatoes. I've also seen various (relatively close - usually 350-375 for 45 minutes to an hour) cooking times.