1. Let duck breasts stand at room temperature for 30 min.
2. Slice through fat in two perpendicular directions in a crosshatch pattern; season with salt and pepper to taste.
3. Preheat oven to 400°.
4. Heat a large oven-safe skillet over high heat; add duck skin-side down. Cook on one side until a moderately dark crust forms and breasts release easily from the pan (about 5 min.).
5. Flip breasts; add onions to the pan, stirring gently to coat onions with rendered fat.
6. Move pan to preheated oven; cook until duck nearly reaches desired doneness (for medium-rare, cook about 12 min. to an internal temperature of 125°; duck will increase to 130° or more as it rests).
7. Remove pan from oven; transfer breasts to a cutting board. Tent loosely with foil; let rest for 10 min.
8. Return onions to oven; roast for 6 min.
9. Slice duck breasts into ½" slices; arrange on a serving platter or individual plates.
10. Using a slotted spoon, remove onions from the pan; serve alongside duck.
11. Top dish with fresh fennel slices; garnish with fennel fronds.

Tasty Tip:

• Take it to the next level by making a delicious pan sauce! After removing onions from the pan the second time, set aside and keep warm. Pour as much fat as possible from the pan; strain and reserve for another use, if desired. Place pan on the stovetop over high heat. Add ½ cup dry white wine, scraping up brown bits with a wooden spoon; cook for 1 min. Add ¾ cup low-sodium chicken broth; bring to a boil. Reduce heat to medium-high; cook until sauce is reduced by at least ⅓; strain sauce. Return sauce to the pan; heat just until it boils. Remove pan from the heat; season sauce with salt and pepper to taste. Whisk in 2 tbsp. cold Kowalski's Unsalted Butter until sauce is glossy and slightly thickened; spoon over duck before garnishing with fennel.