Season and Coat: Pat the chuck roast dry and season it generously with salt and pepper. Roll it through the flour to ensure an even coat and place it atop a layer of sliced onions in your 6-quart slow cooker.

Mix and Pour: Whisk the seasoning packets together in water until well-blended. Gently pour this mixture around the roast, adding carrots and celery to the mix.

Slow Cook: Secure the lid and cook on a low setting for 8 hours.

Pro Tip: Transform the drippings into a savory gravy. Strain the vegetables and channel the liquid into a saucepan over medium heat. In a separate bowl, dissolve 2 tablespoons of cornstarch in 1/4 cup of warm water, whisking until smooth. Integrate the cornstarch mixture with the drippings, maintaining a consistent whisk until the gravy achieves your desired thickness.

Indulge in your effortless slow cooker pot roast, a testament that a delectable, hearty meal need not be labor-intensive. With every bite, appreciate the lusciousness of the roast, the depth of the gravy, and the simplicity of the process, allowing you to savor both the meal and your time!