Dice butter and melt in a pot. Wash basil, dab dry, pluck leaves from the stalks and chop. Wash, clean, quarter and seed the tomatoes. Cut the flesh into small cubes
Remove butter from the stove, pour through a fine sieve and allow to cool slightly. Beat the egg yolks and white wine over a hot water bath until frothy. Gradually fold in the liquid butter. Stir in tomato paste, basil and tomato cubes. Season to taste with sugar, salt and pepper