Prep the produce: wash and dry the lettuce leaves and pat them completely dry (moisture will make them soggy). Dice the tomato, finely dice the red onion, chop the cilantro, mince the garlic if using, and cut the avocado: halve, remove the pit, dice into 1/2-inch pieces and scoop into a bowl. Drying the lettuce and cutting the ingredients first keeps assembly fast and prevents watery cups.

Season and gently warm the shredded chicken (optional): put the 240 g shredded cooked chicken in a skillet over medium heat with 1/2 tbsp olive oil, 1/4 tsp kosher salt, 1/4 tsp ground cumin and a pinch of smoked paprika. Warm for 2–3 minutes, stirring, just until heated through. Warming the chicken helps the spices bloom and meld with the avocado dressing; if you prefer cold chicken, skip this step and use the chicken straight from the fridge.

Make the dressing: in a small bowl whisk together 2 tbsp extra-virgin olive oil, juice and zest of 1 lime (about 1 tbsp juice), minced garlic (optional), remaining 1/2 tsp kosher salt, 1/4 tsp black pepper and 1/4 tsp cumin. Whisking emulsifies the oil and lime so the dressing clings to the chicken and avocado instead of pooling in the bottom of the lettuce cup.

Fold chicken into avocado and dressing: gently toss the warmed (or cold) shredded chicken with the diced avocado, diced tomato, 1/4 of the chopped cilantro, the red onion, a light sprinkle of red pepper flakes or jalapeño (if using), and the dressing. Be gentle so the avocado keeps some texture — overmixing will turn it mushy. The avocado adds creaminess and richness to each cup while the lime and cumin brighten and warm the flavors.

Adjust seasoning: taste the mixture and adjust salt, cumin or lime juice as needed. Because avocado and lettuce mute salt, a final correction ensures the flavors pop when eaten in small lettuce cups.

Assemble the lettuce cups: lay 8 large leaves on a serving platter. Spoon an equal amount of the chicken–avocado mixture into the center of each leaf (about 2 tablespoons per leaf). Two leaves make a serving in this recipe (2 leaves × 4 servings = 8 leaves). The lettuce acts as a crisp, cool wrapper that contrasts with the creamy filling.

Garnish and finish: sprinkle the remaining cilantro over the cups, add an extra pinch of smoked paprika or a thin lime wedge on the side for visual appeal. Serve immediately so the lettuce stays crisp; if you must hold them, keep filling chilled and assemble at the last minute.

To serve like a restaurant: present on a long platter, group two cups per plate, and offer lime wedges and a small bowl of extra chopped cilantro and sliced jalapeños so guests can customize their heat and brightness. The plating makes these feel elevated while still being easy to eat with your hands or a fork.