| 2 | tb | Unsalted butter |
| 1 | c | Minced leek, white and pale green part |
| 1 | lb | Swiss chard (red if possible) stems cut from leaves and chopped into thin slices |
| 3 | lg | Cloves garlic, minced |
| 1/4 | ts | Red pepper flakes, optional |
| 1/3 | c | Canned chicken broth |
| 2/3 | c | Heavy cream (2/3-1cup) |
| 1 | tb | Walnut or similar nut oil (such as hazelnut) |
| | Salt and freshly ground pepper to taste |
| 1/2 | lb | Penne, cooked and drained, according to package directions |
| 3 | tb | Toasted walnut halves, broken into large pieces |
| 2 | tb | Fresh tarragon or parsley, minced, or a combination of both |
| | Freshly grated Parmesan cheese, optional, for garnish |
