Instructions

• Preheat the oven to 325°F. Trim about 1/2 inch from the top of each of the 2 heads of unpeeled garlic to expose the cloves.
• Place each garlic head, cut side up, on a large square of aluminum foil. Drizzle the exposed cloves with 1 tablespoon olive oil and wrap each head tightly in its foil packet.
• Roast the garlic packets directly on an oven rack until the cloves are very tender and golden, about 1 hour 10 minutes. Remove from the oven and let cool until safe to handle. Carefully open the foil to avoid steam.
• Squeeze the roasted garlic cloves from their skins into a medium bowl and mash to a paste with a fork. Add and whisk together the remaining dressing ingredients: 1 cup mayonnaise, 1/2 cup buttermilk, 2½ tablespoons minced fresh chives, 1 tablespoon freshly squeezed lemon juice, 1¼ teaspoons celery salt, and 1/4 teaspoon freshly ground black pepper. Taste the dressing and, if desired, adjust only with additional freshly ground black pepper.
• Prepare the salad vegetables: tear 3 whole hearts of Romaine into bite-sized pieces; halve the 1 pint grape tomatoes; confirm you have 1½ cups small broccoli florets; use the 1 small English hothouse cucumber thinly sliced; use 8 ounces thinly sliced mushrooms; and use 1 small red onion sliced thinly. Combine all these vegetables in a large bowl.
• Pour about half of the roasted-garlic dressing over the vegetables and toss gently to coat. Add more dressing a little at a time until the salad is dressed to your liking (you may not use all of it). Taste and, if desired, add a little more freshly ground black pepper. Serve immediately.