First, a couple of notes on cooking with lavender:
-The leaves as well as the flower blossoms are edible.
-If you don't grow it yourself, make sure that you only use lavender that has been produced for culinary usage (often found in bulk form at health food stores). If it isn't sold in a food store, don't use it (such as that in craft stores).
-A little goes a long way. Too much and your mouth will taste like it was washed out with soap.
Now for some of the items I have done with it:
Lavender ice cream (Lavender & Honey even better!) is a common use. Infuse the cream with the lavender buds by bringing it to a simmer and then take off the heat and cover, letting sit for about 30 minutes.
Lavender orange sorbet (infuse lavender buds into the orange juice).
I've also used lavender and thyme in an herb past rub for roasted lamb.
"English Garden Madeleines" using dried lavender and rosewater in the madeleine batter.
I did a presentation on culinary uses of lavender a dozen years ago and don't quite recall what else I did with it but should be able to pull out the recipes I mentioned above.
If you'd like the recipes, email me at: darin@chefdarin.com and I'll forward them to you.
My wife makes (made up?) a super-quick tasty dish:
Sautee spinach, mushrooms & garlic (2 cloves if you like it garlicky)
layer polenta on the bottom of a baking dish
Add spinach/mushroom/garlic mix
Add black beans (1 can)
Mix in a little salsa
Cover with cheese
Bake at 350 for 20-25 minutes until the cheese is melted.
Best Answer
You can use them to flavor other foods. I've seen cakes and other sweets made with hop flowers. You will probably want a low alpha-acid variety(alpha acid makes the bitter flavor), but both could be interesting.
To use, you could dry the flowers and mill to a fine powder. This can then be incorporated directly into food. I think they could be used similarly to how matcha powder is incorporated into recipes once ground.
You can also use the 'sludge' left over from brewing (mix of hop flowers and yeast and barley bits) as an ingredient in bread, which gives a very interesting flavor. Hops alone would probably add a similar flavor.