Pour your barbecue sauce into your slow cooker—a 5 to 6 quart capacity is ideal, though anything between 4 and 7 quarts will work. To that, add your grated onion along with every drop of its juice. The liquid from the onion is where a lot of the natural flavor lives, so don't discard it. Next, measure out your Worcestershire sauce, brown sugar, apple cider vinegar, and garlic powder directly into the slow cooker. Stir everything together thoroughly with a wooden spoon or whisk until the brown sugar dissolves and you have a unified sauce. This pre-mixing step ensures even seasoning distribution so you don't end up with overly sweet or overly salty spots.

While your sauce mingles, prepare your chicken breasts. Remove them from their packaging and pat them dry with paper towels. Drying the surface helps with browning if you choose to sear them, but honestly, that step is optional and costs nothing extra in terms of flavor—the slow cooking will tenderize the chicken regardless. I skip the searing step when I'm being budget-conscious because the time savings make up for the minimal flavor difference. Place all three pounds of chicken breasts directly into your slow cooker sauce. There's no need to cut them into pieces; they'll cook faster if they're in larger pieces, and larger pieces stay moister during the long cooking process.

Turn each chicken breast over in the sauce so both sides are coated. Cover your slow cooker with the lid and set it to high for 2 to 3 hours, or low for 6 to 7 hours, depending on your schedule. If you have a slow cooker that runs particularly hot (some do), or if you're using smaller chicken pieces, start checking at the 1.5-hour mark. The chicken is finished when the internal temperature reaches 165°F using an instant-read thermometer inserted into the thickest part of the largest breast. Here's the money-saving wisdom: low and slow is actually cheaper for you because it uses less electricity. If you have time, cook on low overnight or while you're at work. You'll save a few cents on your utility bill, and you'll come home to the most incredible aroma.

Once your chicken reaches 165°F, carefully remove each breast to a cutting board. It should be so tender that it nearly falls apart—that's how you know it's perfect. Using two forks, shred each breast into bite-sized pieces, working from one end to the other and letting the meat separate naturally along its grain. You'll end up with beautiful, rustic shreds that aren't too fine but aren't chunks either. Return every bit of shredded chicken to your slow cooker and stir thoroughly so every piece gets coated in that gorgeous sauce. Let it sit in the warm sauce for 5 minutes so the chicken absorbs more flavor.