Elsewhere
| ??? | onions, finely chopped | ??? | |
| ??? | yellow or red sweet peppers, cut into 1 X 5 cm strips | ??? | |
| ??? | butter, unsalted | ??? | |
| ??? | olive oil | ??? | |
| ??? | whipping cream 35% | ??? | |
| ??? | salt [optional] | ??? | |
| ??? | ground pepper to taste [optional] | ??? |
A blender or food processor will be very useful to purée the sauce.
The sauce can be stored up to 1 week in the refrigerator; 3 months in the freezer.