01 - Season both sides of each chicken breast generously with salt, pepper, and garlic powder.
02 - Heat olive oil and butter in a large skillet over medium-high heat. Add chicken breasts and sear for 4-5 minutes per side until golden brown and nearly cooked through. Transfer to a plate and set aside.
03 - Reduce heat to medium. Add chopped shallot and garlic to the skillet; sauté for 2-3 minutes until softened and fragrant.
04 - Pour in chicken broth, scraping up any browned bits from the bottom of the pan. Simmer for 2 minutes.
05 - Stir in heavy cream, Dijon mustard, and chopped dill. Bring to a gentle simmer.
06 - Return chicken breasts and accumulated juices to the skillet. Simmer over low heat for 6-8 minutes until chicken is cooked through and sauce has thickened.
07 - Stir in lemon juice. Taste and adjust seasoning if necessary. Garnish with additional fresh dill and serve hot.