Separate the romaine leaves and rinse them thoroughly in a large bowl of cold water to remove any dirt or grit trapped between the folds of the leaves. Lift the leaves out of the water rather than draining them so sediment remains at the bottom of the bowl. Dry the lettuce completely using a salad spinner or clean kitchen towel. Chop the leaves into bite-sized pieces approximately 3–4 cm wide and place them in a large mixing bowl that allows room to toss the salad comfortably.

If using freshly cooked corn, allow the kernels to cool completely before adding them to the salad. Slice the kernels from the cob using a sharp knife, cutting downward along the cob so the kernels fall away cleanly. If using previously cooked or frozen corn, ensure the kernels are fully thawed and patted dry to prevent excess moisture from diluting the dressing. Add the corn to the bowl with the lettuce.

Wash the tomatoes and pat them dry with a clean towel. Using a sharp knife, dice them into small cubes roughly 1 cm in size. If the tomatoes contain a large amount of watery seed pulp, remove some of the interior before dicing to maintain a crisp salad texture. Add the diced tomatoes to the bowl.

Wash the cucumber and trim the ends. Dice the cucumber into cubes similar in size to the tomatoes so the salad remains evenly textured. If the cucumber contains large seeds, cut it lengthwise and remove the seeds before dicing. Add the prepared cucumber to the bowl.

Peel the red onion and chop it finely into small pieces so the flavor distributes evenly throughout the salad. If the onion flavor is particularly sharp, place the chopped onion in a bowl of cold water for 5 minutes, then drain and pat dry before adding it to the salad. This process softens the pungency and makes the onion milder.

Rinse the cilantro thoroughly and dry it completely. Remove any thick stems and chop the leaves and tender stems roughly. Cilantro provides the bright herbal flavor that defines the salad’s Peruvian character. Add the chopped cilantro to the bowl.

In a small bowl combine the fresh lime juice, olive oil, aji amarillo paste, minced garlic, ground cumin, salt, and black pepper. Whisk the mixture vigorously for about 20 seconds until the oil and lime juice begin to emulsify and form a smooth dressing. The dressing should taste bright, citrusy, slightly spicy, and aromatic.

Gently toss the lettuce, corn, tomatoes, cucumber, red onion, and cilantro together so the ingredients are evenly distributed before dressing.

Pour the lime dressing over the salad and toss thoroughly but gently until all ingredients are lightly coated. The dressing should evenly coat the vegetables without pooling at the bottom of the bowl.

Dice the avocado into 1–2 cm cubes just before serving to prevent browning. Gently fold the avocado into the salad using a spoon or spatula so the cubes remain intact.

Sprinkle the crumbled queso fresco evenly over the top of the salad. The cheese adds creamy richness and subtle saltiness that balances the acidity of the lime dressing.

Transfer the finished salad to a serving bowl or individual plates and serve immediately while the vegetables remain crisp and the avocado is fresh.