1. Remove and discard the any outer wilted leaves from the sprouts.
2. Cut the stem ends crosswise.
3. In a steamer, steam the sprouts just until tender; do not overcook.
4. In a colander, drain sprouts.
5. In a heavy-bottom skillet, add oil and heat it.
6. Add flour and stir for 3-4 minute over low heat until the flour is "toasted" and begins to turn slightly deeper brown in color.
7. Gradually pour milk and stir constantly to avoid lumping.
8. Add the lemon juice, lemon rind and Brussels sprouts.
9. Add a few grains of nutmeg.
10. Stir and cook over low heat until the Brussels sprouts are coated with sauce and the mixture is hot.