Prepare the dressing by placing the fennel seeds in a small saute pan over low heat. Toast, tossing occasionally, about 2 to 3 minutes, or until lightly browned. Crush the toasted seeds with the edge or a pan, in a mortar and pestle, or seal in a plastic bag and roll with a rolling pin.
In a saucepan, place the honey, cider vinegar, salt and pepper, and toasted fennel seeds. Bring to a boil, stirring well. Remove from heat. Whisk in olive oil and season, to taste.
Place the romaine, radicchio, cabbage, and watercress in a large serving bowl. Add warm dressing and toss well. Serve immediately.