This is truly and ridiculously easy. The trick is to get the grill grates very hot. And the result? A lightly caramelized surface and a slightly smoky flavor. The insides stay cool and crisp. It’s quite a contrast of tastes and textures.
Preheat an outdoor grill for high heat, and lightly oil the grate.
Brush each romaine lettuce half with 1/2 teaspoon olive oil.
Cook romaine hearts, cut-side down, on the preheated grill until the cut-side is slightly caramelized but the inside is still cool and crisp, about 2 minutes. Transfer lettuce, cut-side up, to a platter. Sprinkle Parmigiano-Reggiano cheese over lettuce and drizzle balsamic vinegar, sherry vinegar, and 2 tablespoons olive oil over the top.
Per Serving: 88 calories; protein 1.9g; carbohydrates 4.2g; fat 7.5g; cholesterol 1.5mg; sodium 35.2mg.