1. Heat a swirl of olive oil in a pan on medium high heat and add onions and garlic. Cook until onions soften, approx. 3-5 minutes.
2. Add chard and spinach, along with pasta water and cook down until greens just begin to wilt, approx. 1-2 minutes.
3. Add pasta sauce, cream and red pepper flakes. Stir well.
4. Fold in cooked pasta until combined. Salt to taste.