Preparation Heat 2 tablespoons olive oil in heavy large skillet over medium-high heat. Add 1 teaspoon crushed fennel seeds and stir until fragrant, about 30 seconds. Reduce heat to medium-low. Stir in sliced fennel and onion and sauté until vegetables are very tender and caramelized, about 40 minutes. Add 1 tablespoon minced garlic and sauté until tender, about 5 minutes. Season with salt and pepper. (Fennel mixture can be prepared 1 day ahead. Cover and refrigerate.) Preheat oven to 450°F. Heat 1 tablespoon olive oil in another heavy large skillet over high heat. Season pork tenderloins with salt and pepper. Add pork to skillet; cook until brown on all sides, about 10 minutes. Transfer pork to baking sheet; reserve drippings in skillet. Roasts pork until thermometer inserted into center registers 150°F, about 5 minutes. Remove pork from oven; cover with foil and keep warm. Meanwhile, add minced shallots and remaining 1 teaspoon crushed fennel seeds and 1 tablespoon garlic to skillet with drippings and sauté over medium heat until shallots are tender, about 2 minutes. Increase heat to high. Add white wine and boil until liquid is reduced to glaze, about 2 minutes. Add chicken broth and whipping cream and boil until reduced to sauce consistency, whisking often, about 5 minutes. Season sauce to taste with salt and pepper. Rewarm fennel mixture over medium heat until heated through. Divide fennel mixture among 4 plates. Cut pork into 1/2-inch-thick rounds. Arrange pork atop fennel. Spoon sauce over pork. Garnish with fennel fronds.
Preparation Heat 2 tablespoons olive oil in heavy large skillet over medium-high heat. Add 1 teaspoon crushed fennel seeds and stir until fragrant, about 30 seconds. Reduce heat to medium-low. Stir in sliced fennel and onion and sauté until vegetables are very tender and caramelized, about 40 minutes. Add 1 tablespoon minced garlic and sauté until tender, about 5 minutes. Season with salt and pepper. (Fennel mixture can be prepared 1 day ahead. Cover and refrigerate.) Preheat oven to 450°F. Heat 1 tablespoon olive oil in another heavy large skillet over high heat. Season pork tenderloins with salt and pepper. Add pork to skillet; cook until brown on all sides, about 10 minutes. Transfer pork to baking sheet; reserve drippings in skillet. Roasts pork until thermometer inserted into center registers 150°F, about 5 minutes. Remove pork from oven; cover with foil and keep warm. Meanwhile, add minced shallots and remaining 1 teaspoon crushed fennel seeds and 1 tablespoon garlic to skillet with drippings and sauté over medium heat until shallots are tender, about 2 minutes. Increase heat to high. Add white wine and boil until liquid is reduced to glaze, about 2 minutes. Add chicken broth and whipping cream and boil until reduced to sauce consistency, whisking often, about 5 minutes. Season sauce to taste with salt and pepper. Rewarm fennel mixture over medium heat until heated through. Divide fennel mixture among 4 plates. Cut pork into 1/2-inch-thick rounds. Arrange pork atop fennel. Spoon sauce over pork. Garnish with fennel fronds.