Green garlic, I get. Mine are wonderful this spring, stout and delicious.
Both the white stalk and the green leaves are perfect, sauteed in a bit of olive oil.
My perennial leeks have been great, too (they're at the center of the photo). But my experiment with the green garlic roots (laborious to clean) was ho-hum at best.
Yes, they added garlic flavor, but not anything over the top (as the interviewed chef suggested). Perhaps his were different, or perhaps not.