Saute onion and garlic in butter until soft. Add rice and cook, stirring, for one minute. Add broth, salt and pepper. Bring to a boil, then reduce to low, cover and cook for 20 minutes. Remove from heat and let stand for 5 minutes. Meanwhile, beat together egg yolks, lemon juice, and nutmeg.
Gradually stir egg mixture into rice, mixing well. Cover and let stand 2 to 3 minutes longer.