Tuna loin fillets with a sesame-dressed salad and wilted pok choi

For the sesame dressing:
300ml sesame oil
75ml rice wine vinegar
25g sesame seeds, toasted
Juice and finely grated zest of 1 lime
Salt and freshly ground black pepper
For the salad:
1 x 200g punnet of bean sprouts
2 medium red peppers, finely sliced
2 medium carrots, peeled and very finely sliced
200g rice noodles
5 spring onions, finely chopped
1 small bunch of fresh coriander, finely chopped
For the tuna loin fillets:
4 x 200g tuna loin fillets
Salt and freshly ground black pepper
Extra virgin olive oil
For the garnish:
1 bunch of baby pak choi
2 lemons, cut in half