Heat Olio Taibi Biancolilla extra virgin olive oil in a large stainless steel braiser or enameled dutch oven over medium heat.
Add onion, garlic, and red pepper flake. Sauté until softened, about 3-5 minutes. Do not let garlic burn, lower heat if it starts to take on color.
Add cabbage, apples, and salt. Stir into onion mixture, to begin wilting of cabbage, stirring regularly.
Once cabbage has wilted down a bit, approximately 5 minutes, add apple cider vinegar, and stir to distribute.
Cover pot with lid, lower heat to medium-low, and cook slowly for 60-90 minutes, stirring occasionally, until melty and soft.
Serve warm, garnished with parsley if desired.