Preheat oven to 300° with rack in the middle.
Season bird with salt and pepper, including inside the cavity.
Whisk together the gochujang and ¼ cup of olive oil. Grate or mince a couple of garlic cloves, and add that to the gochujang oil. Do the same with the ginger.
Cut what’s left of the head of garlic in half, and put one half of it inside the bird.
Coat the chicken with roughly half of the gochujang oil. Reserve some of the gochujang oil to put on the veggies.
Chop the veggies into medium-sized chunks and arrange them around the outside of your skillet, placing the chicken in the middle.
Coat the veggies with a mixture of the remaining gochujang oil and the extra 2 Tbsp of oil. Season with salt and pepper.
Slow-roast until the potatoes are tender and the chicken skin is a deep reddish-golden brown, about 2½-3 hours.
Let everything rest for 10-15 minutes before cutting into the chicken.