Cut the vegetables into large pieces. 

Heat a pot and sauté the vegetables until golden in the oil.

Add paprika and chili powder and let it sauté for a moment.

Add wine and let it reduce a bit.

Add the stock to the pot and let the liquid reduce again.

Now pour in the milk and let it also reduce a bit.

Finally, add the cream and let the sauce simmer for a few minutes.

Season to taste with salt, pepper, lemon juice, and gastrique.

If you find the vegetable pieces too large, you can blend the sauce with a hand blender.

Blend all of the sauce, or just partially, as we did. We preferred a sauce with some texture, so we left some whole pieces of vegetables in.