If the potatoes are smaller than golf balls, leave whole. If they are larger than golf balls, cut in half. Place the potatoes in the crock of a large slow cooker. Cover and slow cook on high for 2 hours, or on low for 3-4 hours.: The scents here are subtle at first, a raw earthy note from the potatoes that tells you they are fresh and ready; you want uniform pieces so they cook evenly, which affects final texture. When you cut larger potatoes in half you'll expose more surface area for the melted butter and minced garlic to cling to, creating pockets of flavor inside. A common error is leaving wildly varying sizes, which produces some mushy pieces and some underdone ones. Aim for similar sizes for consistent doneness, and the visual cue to watch for is even coloring and fork tender centers when finished.
Once the potatoes are halfway cooked, lay the chicken over the top. Add the minced garlic, herb springs, 2 teaspoons salt and 1/2 teaspoon ground black pepper. Pour the melted butter over the top.: As the cooker warms you will notice the aroma of warmed starch rising gently, and steam beginning to circulate. Cooking at high concentrates flavors more quickly, while low yields a more gradual melding of tastes and softer textures. I prefer low when I have time because the potatoes absorb more of the buttery juices, resulting in a richer mouthfeel. Avoid lifting the lid too often, because each peek releases heat and slows the process; instead use time and a gentle squeeze test to judge doneness.
Cover and continue slow cooking until the chicken is cooked through, 1 1/2 – 2 hours on high, 3-4 hours on low. Stir a couple times while cooking.: At this point the slow cooker will smell faintly sweet and earthy from the potatoes , and adding the chicken on top allows its juices to drip down, seasoning the base. The minced garlic begins to soften and perfume the steam, while the herbs release essential oils when heated. Pouring the melted butter creates a lacquer that encourages browning of exposed edges and keeps the meat moist. A mistake I often see is skimping on seasoning; measure the salt and pepper, because the slow process can mute sharpness unless properly balanced.
Cover and continue slow cooking until the chicken is cooked through 1 1 2 to 2 hours on high 3 to 4 hours on low: As the cooker finishes, listen for a gentle simmer and watch for a glossy surface where the butter has concentrated. The chicken should reach a reliably opaque interior and the juices should run clear when pierced; those are the primary visual cues that it is safe and done. Leaving it on low for the full time creates the most tender results, especially for thigh meat, while high is handy when time is tight. Avoid overcooking the lean pieces, which can get stringy if left too long on high heat.
Stir a couple times while cooking: During these stirs you will hear a soft scraping as the potatoes shift and the butter redistributes, which helps avoid hot spots and ensures the flavors are evenly shared. Stirring also lets you check for doneness and adjust seasoning incrementally. Be mindful not to stir so vigorously that you break apart the potatoes into mush; gentle turning is enough. A typical misstep is stirring too frequently, which lowers the internal temperature and prolongs cooking, so limit it to a couple of times.
