Dany, the offbeat brewer at Fantôme, will try anything, and the results are always interesting. A beer made from dandelions would be worth a try if only because no one has ever brewed one before, but the great news is that this is actually a very good beer. 
Dany and some cohorts get busy every spring picking bushels of dandelions that grow in the fields around the picturesque farmhouse brewery. The yellow flowers are removed and dried in the sun, then soaked in water for a few days. The thick, dark dandelion “tea” that results is the basis for the Pissenlit, which is made also from traditional barley malt and hops. It resembles a classic saison beer – golden spritzy brew, strong and very flavorful, with a good hop bite. You may have to strain to taste the dandelions, but you know they’re in there. 
It should be noted that uncooked, the dandelion has a diuretic effect and is known in France as Pissenlit (literally, "wet the bed" - this also happens to be the British folk-name) for precisely this reason.