Steps

• Peel the onions and chop them coarsely. Peel the carrots and cut them into pieces. Wash the celery and cut it into pieces, removing the strings. Transfer the vegetables to the chopper glass and blend to obtain the desired size: you can make it finer or coarser. In a low-edge casserole, heat the oil and then add the vegetables. Season with salt and let it brown, stirring occasionally until they are wilted and soft, keeping the flame first lively and then lowering it until you have a soft and dry consistency. Let it cool, then transfer the mixture into ice cube molds (mine are very convenient because they have a lid and you can close and stack them). Store the molds in the freezer, and when the mix for sauté is frozen, take it out (with these molds that have a soft base, releasing the cubes is very easy and fast) and store it in a reusable food bag.