Dear __________,
I cannot thank you enough for the delicious lasagna you prepared for us. Having that nutritious, ready-made meal available to us during the first week of caring for our newborn was a real lifesaver! We are grateful for your thoughtfulness and friendship. In a few weeks we hope to host a small party to introduce the baby to family and friends. We hope you’ll be able to come.
Love and kisses,
(YOUR NAME HERE)