The lacy fronds have a delicate anise flavor and are so tender that they practically melt in your mouth. Think of them as herbs, just like dill or tarragon. They don't hold up well to long cooking, but are best used fresh.
The stalks also have that signature mild licorice flavor, but are much tougher. To use them raw, I like to chop them very finely to break apart their tough fibers. They also do well if cooked.
1. Add the Leafy Fronds to Salads: Strip the fronds from the stalks and toss them in your next green salad. They'll add just the faintest hint of licorice to each bite.
2. Make Fennel Pesto: As Sara Kate would be quick to point out, any green is pesto waiting to happen. Try tossing fennel pesto with pasta or rubbing it onto meat before roasting.
3. Use Stalks and Fronds for Cooking Fish: Fennel and fish have been best friends since the dawn of cooking. Whether you're grilling, poaching, or steaming, laying a few stalks and fronds alongside the fish will infuse the fish with sweet fennel-tastic flavor.
4. Juice 'Em Up: If you have a juicer, you need look no further. You won't get a lot of juice from the tops (unless you have a lot of fronds!), but what you do get can be mixed with other juiced fruits and vegetables.
5. Save for Stock: If inspiration fails to strike, at the very least you can stick the stalks and fronds in the freezer and save them for the next time you make vegetable or chicken stock. It's not for everyone, but I really like the sweet undertone that fennel gives to stocks.
What are your favorite ways for using fennel tops?
Related: From the Spice Cupboard: Fennel Seed