Tomatoes Devilled

From 1922:

Slice 5 or 6 firm tomatoes, place them in a saucepan containing a little hot butter, and let them cook very slowly for a few minutes. Mix 2 yolks of 2 hard-boiled eggs and 2 oz. of butter together, stir in 2 tablespoonfuls of vinegar, add half a teaspoonful of made mustard, 1 saltspoonful of salt, 1 saltspoonful of sugar, and a good pinch of cayenne, and turn the whole into a small stew pan. When thoroughly hot, beat and add 2 eggs, and stir until the mixture thickens. Place the tomatoes on a hot dish, pour the sauce over, and serve.