Preheat oven to 350℉ and lightly grease a baking dish.: You will notice the smell of warm metal as the oven comes to temperature, and preheating ensures even cooking throughout the chicken . Using a lightly greased dish helps the crust release cleanly when plated, avoid sticking that can tear the meat. If the oven is not fully preheated you may face uneven cooking and a longer overall time, so always wait until it reaches 350℉ before inserting the dish. A common mistake is placing the pan into a lukewarm oven, which changes timing and texture.
Dip the chicken breasts in water and shake off the excess.: The water helps the flour and seasoning adhere, and you should hear a faint slap as excess drips away before coating. This creates a thin layer that binds the flour mixture to the surface, improving crust formation. If too much water remains, the flour can clump and create a pasty coating, so shake well. Avoid leaving the breasts soaking, which can dilute seasoning and alter texture.
Combine the flour and seasonings, then coat the chicken with the flour mixture.: When you mix the all purpose flour , kosher salt, paprika, herbs de Provence, and black pepper you will smell the spice medley come alive, and the pale flour will take on warm hues. Coating each breast evenly ensures every bite gets flavor and a pleasant exterior texture. Tap off excess flour so the coating is light, this prevents a gummy crust. A typical error is overcoating which results in a heavy, chalky exterior rather than a delicate crust.
Place chicken breasts into the prepared baking dish.: Arrange the breasts with space around each piece so heat circulates and the surface can brown slightly. You might hear a soft sizzle as the warm pan accepts the meat, and visually the coated breasts will glisten faintly from the water left in the coating. Crowding leads to steaming and uneven browning, so give them room. If one breast is much thicker than another, it may need extra time or light pounding to even thickness.
Cut the butter into small squares and arrange on top of the chicken.: As the butter melts it will baste the top of each breast, producing glossy, golden pockets of flavor. Small squares melt more evenly than one large slab, and the aroma of butter warming against the seasoned flour is deeply appealing. If you place the pieces too close together they may pool excessively in one area, so space them for even distribution. Using cold, hard butter without softening slightly can make cutting difficult; let it sit briefly to ease slicing.
Bake in the preheated oven for 15 minutes.: After this initial bake you will notice the butter beginning to melt and the edges of the coated surface starting to firm and take on a faint golden tone. This short burst begins the cooking process and helps set the exterior before adding the milk solution. Opening the oven prematurely can drop temperature and extend cook time, so try to avoid peeking. A common misstep here is assuming the meat is done after this phase, it is only the first stage of cooking.
Combine dry milk powder and hot water in a bowl. Pour the milk around the chicken.: Stir until the powder disappears and you have a smooth, warm milky liquid, which will steam in the oven and keep the chicken moist. You should see a gentle swirl as you pour the liquid around the breasts, not over them, creating a shallow bath that will simmer quietly. If the powder is not fully dissolved you may feel a gritty texture on tasting, so whisk thoroughly. Avoid pouring too much liquid on top of the breasts, which can wash away the coating instead of surrounding it.
Cover with aluminum foil and return to oven.: Covering traps steam and encourages gentle, thorough cooking, which maintains tenderness. As the foil seals, you may hear faint bubbling from the milk bath and smell the meld of butter and seasonings intensify. Leaving it uncovered at this stage risks drying the tops and burning the butter, so tent the foil securely. A common error is sealing too tightly and not allowing any steam escape, which can lead to an overly soggy texture in some ovens.
Bake at 350℉ for 30-40 more minutes, or until internal temperature reaches 165℉. Enjoy!: During this longer baking window the kitchen fills with a deep savory aroma and the milk bath will barely shimmer as it simmers. Use an instant read thermometer to confirm the thickest part of the chicken reads 165 degrees for safe, juicy results. If you skip the thermometer you risk undercooking or overcooking; visual clues like clear juices and a firm but springy texture help, but the check with temp is best. Avoid letting it go much beyond the target temperature, which can dry the meat and dull the buttery finish.