In a large pot (or crockpot), combine the cleaned neck bones, water or anchovy stock, garlic, onion, gochugaru, gochujang, doenjang, soy sauce, and sesame oil. Bring to a boil, then reduce to a simmer and let cook covered for 1.5–2 hours until the meat is fall-off-the-bone tender. If using a neck bones in crock pot method, set it on low for 6–8 hours.