Cook fennel and onion in 2 tbsp. extra-virgin olive oil in a large frying pan over medium-low heat until well caramelized, about 30 minutes. Add saffron, cayenne, and paprika; cook until fragrant, 1 minute.
Remove from heat and add vinegar, broth, zest, rosemary, and salt. Let cool. Whisk in 5 tbsp. more extra-virgin olive oil.
Note: Nutritional analysis is per tbsp.
Servings 0
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.