Season & Sear: Season both sides of the chicken breasts with salt and pepper. In a large skillet, heat oil or butter over medium-high heat. Add chicken and cook 5–6 minutes per side, until golden brown and cooked through (165°F internal temperature). Remove and set aside.
Sauté Aromatics: In the same pan, reduce heat to medium. Add onion and garlic, cooking until soft and fragrant, about 2 minutes.
Make the Roux: Sprinkle flour over the onions and garlic. Stir constantly for 1 minute to cook the flour.
Add Liquids: Gradually whisk in chicken broth and milk. Simmer until the gravy thickens, about 3 minutes.
Combine & Simmer: Return chicken to the skillet. Add thyme and Worcestershire sauce. Simmer another 5–7 minutes, spooning gravy over chicken.
Serve: Serve hot with mashed potatoes, rice, or noodles. Garnish with fresh parsley.
Notes
For extra richness, use heavy cream instead of milk.
Chicken thighs can be used instead of breasts for juicier results.
Add sautéed mushrooms or peas for more texture and nutrition.
To freeze: Cool completely, transfer to a container, and freeze for up to 3 months.