How to Make It
Preheat broiler with oven rack in top position.
Combine 1 tablespoon oil, butter, salt, pepper, and haricots verts in a bowl; spread in a single layer on a foil-lined rimmed baking sheet. Add garlic cloves to pan. Broil 5 minutes or until beans just begin to char. Add tomatoes and shallot; broil 5 minutes or until tomatoes start to break down.
Remove skins from garlic cloves; discard. Place garlic pulp in a bowl; mash. Stir in remaining 1 tablespoon oil and vinegar. Drizzle garlic mixture over green bean mixture; toss.