Heat the olive oil in a large frying pan. Add the onion and cook for 2-3 minutes. Add the garlic, carrots, and celery, and cook for another 3-4 minutes.
Place the mixture in a sprayed crock pot; add 1 cup of lentils, 2 cups of stock, red pepper flakes, and salt and pepper. Pour in the stock.
Cook on low for 4 hours, or on high for 2-3, until the lentils are soft.
Allow to cool. Shred the cabbage. Make the dressing.
Serve on top of a bed of shredded cabbage; drizzle with dressing and garnish with parsley.
Simmer til lentils are soft (or use slow cooker).