- In a large pot, cover greens with 1 inch of water. Bring to a boil, reduce heat, and simmer until just tender, about 45 minutes. Drain well.
- Wipe out pot, add butter, and melt over medium heat. Add onion, garlic, and chile de arbol. Sauté until onion softens.
- Add tomatoes and cook 5 minutes. Add cooked turnip greens and chicken stock, raise heat to high, and boil 5 minutes. Reduce heat to medium low and taste for seasoning, adding salt and more chile de arbol if desired. Simmer 15 minutes and taste again for seasoning.