Ingredients

• 1/4 medium white onion, quartered
• 1 small tomatillo, husk removed
• 1 jalapeño, sliced, seeds removed
• 1 garlic clove
• 1/4 avocado, chopped
• 1/4 cup chopped fresh cilantro leaves
• 1/4 cup olive oil
• 1 tablespoons fresh lime juice
• Kosher salt
• Freshly ground black pepper
• 1 small poblano chile
• 2 heads of romaine lettuce, outer leaves removed, halved lengthwise
• 2 tablespoons olive oil
• Kosher salt
• 1 avocado, chopped
• 1/4 medium white onion, finely chopped
• 1 tablespoons fresh lime juice
• 2 ounces Cotija cheese, finely grated
• 1 tablespoons chopped cilantro stems

Instructions

1. Bring onion, tomatillo, jalapeño, garlic, and 2 cups water to a boil in a small saucepan. Reduce heat and simmer until onion is very tender, 6–8 minutes; let cool. Drain, reserving cooking liquid.
2. Purée onion mixture with avocado and cilantro leaves in a blender. With motor running, gradually add oil and 2 tablespoons cooking liquid and blend until combined.
3. Add lime juice; season with salt and pepper.
4. Prepare grill for medium-high heat. Grill poblano, turning occasionally, until charred and blistered, 6–8 minutes. Let cool. Peel and finely chop.
5. Drizzle cut sides of romaine with oil; season with salt. Grill, cut side down, until charred, about 3 minutes. Turn and grill just until warmed through, about 30 seconds.
6. Spoon dressing onto plates and top with romaine, charred side up, avocado, onion, and poblano. Drizzle with lime juice; season lightly with salt. Scatter Cotija cheese and chopped cilantro stems over.