Season and sear the chicken. Pat the chicken breasts dry with kitchen paper. In a small bowl, mix the smoked paprika, cumin, garlic powder, onion powder, half a teaspoon of salt, and a good grind of pepper. Rub this spice mix all over the chicken. Heat a large frying pan over a medium-high heat and add a tablespoon of olive oil. When the oil shimmers and a drop of water sizzles on contact, lay the chicken in the pan. You'll hear a lovely, aggressive hiss. Cook for 5–6 minutes per side, until the chicken is deeply golden brown and feels firm to the touch. The aroma of the toasting spices will fill your kitchen.

Rest and shred. Transfer the cooked chicken to a plate and let it rest for at least 5 minutes. This is crucial so the juices redistribute, keeping the meat moist. Once rested, use two forks to shred the chicken into bite-sized pieces. You'll see the steam rise as you pull it apart. Taste the shreds and adjust seasoning if needed.

Make the guacamole. Cut the avocados in half, remove the stones, and scoop the flesh into a mixing bowl. Add the lime juice and zest. Use a fork to mash the avocado to your preferred consistency — I like it with a few chunky bits left for texture. Fold in the diced red onion, chopped coriander, and the jalapeño if using. Season with a pinch of salt. The guacamole should be vibrant green and smell fresh and zesty.

Assemble the first quesadilla. Wipe the frying pan clean and place it over a medium heat. Add a tiny drizzle of olive oil or a quick spray of cooking oil. Lay one tortilla in the pan. Immediately scatter about a quarter of the grated cheese over the entire surface. Spoon a quarter of the shredded chicken over half of the tortilla (the half you'll fold over). Once the cheese begins to melt and the bottom of the tortilla is a pale, golden brown — you'll see the edges turning opaque — carefully fold the empty half over the filling, creating a half-moon.

Toast until golden and crisp. Press down gently on the quesadilla with a spatula. Cook for 2–3 minutes on the first side, until the bottom is a deep, mottled gold and you can hear a gentle crackle when you lift the edge. Flip carefully using the spatula and cook the other side for another 2 minutes. The cheese should be fully melted and starting to ooze out at the edges, forming crispy, lacy bits. The entire kitchen will smell gloriously of toasted tortillas and melted cheese.

Rest and repeat. Transfer the cooked quesadilla to a cutting board and let it rest for a minute. This helps the cheese set slightly so it doesn't all spill out when you cut it. Repeat the process with the remaining three tortillas, adding a tiny bit more oil to the pan for each one.

Slice and serve. Using a sharp knife or a pizza cutter, slice each quesadilla into three wedges. Arrange the wedges on a plate with a generous dollop of the fresh guacamole on the side. The first cut should produce a satisfying crunch, revealing the molten, cheesy interior.