(Note: this "Lady of the Lake" is different from the arthurian "Lady of the Lake.")
In the welsh story associated with the lake Llyn y Fan Fach, Gwyn attempts to woo the "Lady of the Lake" by giving her bread.
He stood on the brink, gazing fixedly at the maiden, and straightway knew that he loved her. As he gazed, he unconsciously held out to her the barley-bread and cheese which his mother had given him before he left home. The lady gradually glided towards him, but shook her head as he continued to hold out his hand, and saying:
O thou of the crimped bread,
It is not easy to catch me,
(Thomas, Jenkin, The Welsh Fairy Book [available online].)
Gwyn tries to woo her with completely baked bread and with unbaked dough. Neither attempt is successful. However, when he uses half baked bread, he is successful:
The shades of night began to fall, and Gwyn was about to depart in sore disappointment, when, casting a last farewell look over the lake, he beheld some cows walking on its surface. The sight of these beasts made him hope that they would be followed by the Lady of the Lake, and, sure enough, before long the maiden emerged from the water. She seemed lovelier than ever, and Gwyn was almost beside himself with joy at her appearance. His rapture increased when he saw that she was gradually approaching the land, and he rushed into the water to meet her, holding out the half-baked bread in his hand. She, smiling, took his gift, and allowed him to lead her to dry land.
What's so special about half baked bread?