Fennel rye saison?

Anybody ever brewed with fennel? I am putting together a recipe for a spiced rye saison, but am not sure just how or when to use the fennel that I am tasting on my mind’s tongue. Seeds in the boil? Fresh green leaves in the keg?

I make a Rye Ale, and I’ve considered using fennel. I’d probably toast a teaspoon or so of the seeds, crush 'em a bit and add to secondary. I’ve never done it though; I’d be interested in your results, however you decide to go.