Ingredients

• 1 1/2 cups white wine vinegar
• 1/2 cup sugar
• 1/2 cup water
• 3 Turkish bay leaves
• 1/2 teaspoon dried crushed red pepper
• Coarse kosher salt
• 1 to 1 1/4 pounds red onions, thinly sliced
• 1/4 cup white wine vinegar
• 1/2 teaspoon Dijon mustard
• 1/2 cup olive oil
• 1/2 cup crumbled blue cheese
• 4 hearts of romaine, each quartered lengthwise Crumbled blue cheese (for garnish)

Instructions

1. Combine first 5 ingredients and 1/4 teaspoon coarse salt in medium saucepan. Bring to simmer over medium heat. Add onions and stir to blend; return to simmer and cook 2 minutes. Remove from heat; cool to room temperature, about 1 hour. Season with freshly ground black pepper and more salt, if desired. DO AHEAD: Can be made 1 day ahead. Cover; chill.
2. For salad: Prepare barbecue (medium- high heat). Combine vinegar and mustard in bowl. Gradually whisk in oil. Season with coarse salt and pepper. Mix in 1/2 cup cheese. Brush cut sides of romaine with olive oil, then sprinkle with coarse salt and pepper. Grill until cut sides are lightly charred, about 2 minutes per side. Divide grilled romaine among plates. Top with vinaigrette, pickled onions, and blue cheese.
3. Prepare barbecue (medium- high heat). Combine vinegar and mustard in bowl. Gradually whisk in oil. Season with coarse salt and pepper. Mix in 1/2 cup cheese.
4. Brush cut sides of romaine with olive oil, then sprinkle with coarse salt and pepper. Grill until cut sides are lightly charred, about 2 minutes per side.
5. Divide grilled romaine among plates. Top with vinaigrette, pickled onions, and blue cheese.