Tomato-Chive Butter: In small saucepan over med-hi heat combine shallots, wine and vinegar; simmer until 2 tbsp remain.
Add cream and return to simmer for 2 1/2 minutes.
Remove from heat and begin whisking in butter, cube by cube; as you add cubes you may want to place pan back over very low heat briefly; continue whisking in butter until it is all incorporated.
Pour into a warm bowl and add tomatoes, chives, lemon juice, salt and pepper.
Fish: Position broiler rack 4 to 5 inches from heat.
About 10 minutes before sauce is done sprinkle fish with salt and pepper; place on an oiled broiler rack and broil 4 to 5 minutes a side or until cooked through; place on a serving plate and top with about 3 tbsp butter sauce.