1

Preheat the oven to 400°. Heat 1 tablespoon of the oil in a large saucepan over moderate heat for 1 minute. Add the onion and sauté, stirring occasionally, until soft -- 5 minutes. Transfer the onion to an ungreased 3-quart casserole.

2

Add the remaining oil to the saucepan and heat for 1 minute. Reduce the heat to low, whisk in the flour, and cook, stirring constantly, until bubbling -- about 3 minutes. Stir in the milk, marjoram, salt, and pepper, and cook, stirring constantly, until slightly thickened -- 3-5 minutes. transfer 1/2 cup of the cream sauce to a medium-size bowl, add the cooked noodles, mix gently, and set aside.

3

Add the cheese, spinach, and carrots to the remaining sauce and cook over low heat, stirring constantly, for 2 minutes. Transfer to the casserole with the onion. Add the beef and egg to the casserole and mix well. Pack down lightly.

4

Layer the noodle mixture on top of the beef. Cover the casserole with foil and bake for 25 minutes. Uncover and bake until the noodles are golden and the mixture is set -- 15-20 minutes.