Heat your oven to 180°C/Fan 160°C/Gas 4. Chop two of the tortillas into little triangles. Spread them out on a baking tray. Bake for 8-10 mins till they’re golden brown and crisp. (See our tip below on what to do with your leftover tortillas.)
Peel and finely slice the red onion. Finely zest and juice one of the limes. Put the lime juice in a bowl. Stir in 1 tbsp caster sugar with a good pinch of salt. Stir in the sliced red onion. Put to one side.
Drain the sweetcorn. Warm a dry frying pan over a medium heat. Add half the sweetcorn kernels. Fry, stirring now and then, for 4-5 mins till the corn is toasted, golden and starting to pop.
Tip the toasted sweetcorn into a bowl. Finely slice the chilli. Add it to the sweetcorn with the lime zest and a pinch of salt and pepper. Stir to mix.
Separate the lettuce leaves and shred them. Peel and dice the cucumber. Halve the cherry tomatoes. Tumble the salad into a bowl. Juice the remaining lime. Whisk it with 1 tbsp oil and some salt and pepper. Toss with the salad in the bowl.
Slice the chicken breast mini fillets into long thin fingers. Warm 2 tsp oil in the frying pan. Add the chicken. Cook and stir for 8-10 mins till the chicken is golden and cooked through.
Scatter the nachos over two plates or shallow bowls. Layer up with the salad and toasted sweetcorn. Top with the chicken. Heap on the red onions. Drizzle over lime juice from the red onion bowl. Garnish with coriander leaves to serve.