Wash and dry romaine leaves thoroughly, then chop into bite-sized pieces (about 6 cups packed). Drain and rinse canned black beans in a fine-mesh strainer. If using fresh corn, cook and cut kernels off the cob; if using frozen, thaw and pat dry. Dice tomatoes, thinly slice the red onion, julienne the roasted red peppers, and dice the avocado. Chop cilantro and squeeze the lime.

Season & combine

In a large mixing bowl, add the chopped romaine, corn, black beans, diced tomatoes, roasted red peppers, and sliced red onion. Sprinkle 1 tsp salt and 1/2 tsp black pepper over the vegetables and toss gently to combine. Squeeze the juice of 1 lime over the mixture and toss again. Taste and adjust salt/pepper as needed.

Add avocado & cilantro

Gently fold in the diced avocado and 2 tbsp chopped cilantro just before serving to prevent the avocado from mashing. Reserve a few avocado pieces for garnish if desired.

Spicy Ranch Dressing

In a medium bowl, whisk together 1/2 cup mayonnaise, 1/4 cup sour cream (or Greek yogurt), and 1/4 cup buttermilk until smooth.

Add 1 tbsp fresh lime juice, 1 minced garlic clove, 2 tbsp finely chopped cilantro, 1 tsp smoked paprika, 1/2 tsp ground cumin, and 1 tsp finely minced chipotle in adobo (or preferred chili paste). Whisk to combine.

Season the dressing with 1/2 tsp salt, 1/4 tsp black pepper, and 1/2 tsp honey if using. Taste and adjust heat or acidity: add more chipotle for heat, more lime for brightness, or a splash more buttermilk to thin.

Cover and refrigerate the dressing for at least 15 minutes to let flavors meld. Stir again before serving.

To Serve

When ready to serve, either toss the salad with enough dressing to lightly coat (about 1/3 to 1/2 cup dressing for 6 cups salad) or plate and drizzle dressing over individual portions. Garnish with extra cilantro and reserved avocado pieces.

Serve immediately. Leftover dressing will keep refrigerated in an airtight container for up to 5 days; salad components (without avocado and dressing) will keep 2–3 days separately.