Preparation Heat lightly oiled grill pan over moderately high heat until hot but not smoking. Meanwhile, pat chicken dry and coat with 1 tablespoon oil, then sprinkle with 1/2 teaspoon salt and 1/4 teaspoon pepper. Grill chicken, turning over once, until just cooked through, 14 to 16 minutes total. While chicken grills, blend garlic, lemon juice, mustard, anchovy paste, and remaining 1/2 teaspoon salt and 1/2 teaspoon pepper in a blender until combined. With motor running, add remaining 7 tablespoons oil in a slow stream, blending until emulsified. Transfer chicken to a cutting board and cut into 1/2-inch-thick slices. Toss chicken with 2 tablespoons dressing in a large bowl. Add romaine, cheese, remaining dressing, and croutons and toss.
Preparation Heat lightly oiled grill pan over moderately high heat until hot but not smoking. Meanwhile, pat chicken dry and coat with 1 tablespoon oil, then sprinkle with 1/2 teaspoon salt and 1/4 teaspoon pepper. Grill chicken, turning over once, until just cooked through, 14 to 16 minutes total. While chicken grills, blend garlic, lemon juice, mustard, anchovy paste, and remaining 1/2 teaspoon salt and 1/2 teaspoon pepper in a blender until combined. With motor running, add remaining 7 tablespoons oil in a slow stream, blending until emulsified. Transfer chicken to a cutting board and cut into 1/2-inch-thick slices. Toss chicken with 2 tablespoons dressing in a large bowl. Add romaine, cheese, remaining dressing, and croutons and toss.