In a large bowl, beat the eggs, milk, lemon juice, lemon rind, and oil together until well blended. Add separately the flour, sugar, baking powder, nutmeg, and poppy seeds, stirring well after each addition. Fold in the walnuts.

Spoon the batter into greased or paper-lined muffin tins, filling about three-fourths full. Bake in a preheated 400 degree oven until a toothpick inserted in the center comes out clean, about 20 minutes.