I don’t think they are a hybrid, but a leek bred to have garlic-like flavor.
Row 7 wrote:
Allium porrum
During his decades of working with garlic and leeks from all over the world, allium breeder Hans Bongers identified a unique leek with uniformly straight shafts and a distinct garlicky flavor. He spent 10 years developing this trait, creating a cross that would express the sweetness of leeks with the mild, savory notes of garlic. The result of this love match, Sweet Garleek was first introduced to us by Bejo Seeds and immediately opened up a whole new world of allium possibilities.
While on the topic of Row 7, their Koginut and Centercut squashes are ones that I have tried, and they are very good. Even though Koginut is an F1, they breed relatively true, so seeds saved don’t deviate excessively from the original.