Bring enough salted water to the boil in a larger saucepan so that all the vegetables can steep for 3 minutes. Turn off the heat immediately after adding.
While the vegetables are steeping, sweat the onion cubes in oil. Add tomato paste and roast a little. Deglaze with the white wine and bring to the boil. Pour in the cream, sprinkle in sugar, pepper and salt, stir well and let everything simmer a little. Reduce heat a lot. Sauce should have a creamy consistency, but the fat shouldn't separate itself. If that happens, just add some more wine and stir everything well. Season to taste.
Now drain the vegetables after the 3 minute cooking time has elapsed, drain them well and add them to the tomato cream sauce. Mix everything together well.
Arrange the vegetable strips in the middle of a plate, place a portion of the fillet with the potato coating on top and ................ just let it taste. A dry white wine goes well with it.