I think this cauliflower cream harmonise perfect with tomatoes. It is very easy to prepare and looks pretty.
1 tablespoon mustard
1 tablespoon sour cream
1 egg yolk
1 cooked egg yolk
0,5 dl oil
Cook cauliflower in stok and puree with a mixer.
Stir egg yolks with a hand mixer and add slowly oil. Add mustard, sour cream, salt and pepper, cauliflower and grated onion. Serve in tomatoes.