Heat a splash of oil in a frying pan and cook the onion until soft and translucent.
Add the mince and brown it well, then stir in the taco seasoning. Set aside.
Salsa dressing
Mix all the dressing ingredients together and season to taste with fresh lime juice, salt and freshly ground pepper. Keep chilled until ready to serve.
Assembling the salad
Cook the pasta according to the packet instructions, then rinse it under plenty of cold water. Leave it to drain in a sieve.
Put the pasta, vegetables, beans, beef and cheddar in a large bowl. Pour over the dressing and toss everything together well. Season to taste with salt and freshly ground pepper.
Divide the salad between 4 bowls and serve, if you like, with a few crushed tortilla chips on top.