| 1 | In a 3-quart heavy pot, preferably cast iron or copper, melt the butter over low heat, add the onions and cook, covered, for 15 minutes. |
| 2 | Uncover and continue to cook until the onions turn a deep golden color, about 30 to 40 minutes, depending on your pot. |
| 3 | Stir frequently. |
| 4 | Add the broth and the nutmeg, cover and bring to a boil. |
| 5 | Reduce heat and simmer for 15 minutes. |
| 6 | Meanwhile, in a small pot, bring the beer to a boil over medium heat and boil until the liquid has reduced by half. |
| 7 | Remove from the heat and add the cheddar cheese, stirring until melted. |
| 8 | Transfer this mixture to a blender. |
| 9 | Add 1 cup of the onion soup and blend until smooth. |
| 10 | Reserve. |
| 11 | Remove the onion mixture from the heat and strain. |
| 12 | Reserve the liquid. |
| 13 | Transfer the onions to a blender or food processor and puree until very smooth. |
| 14 | Return the puree to the pot, add the reserved liquid and the cheddar cheese mixture. |
| 15 | Taste for salt and pepper. |
| 16 | Serve piping hot in a tureen. |
