Cook the pasta in a large saucepan of boiling water for 10 minutes, or according to the packet instructions. About 3 minutes before the pasta is ready, add the sugar snap peas to the pan and continue boiling until the pasta is al dente and the peas are tender but crisp. Drain both into a colander, then tip them into a large serving bowl.
Drizzle with 1 tablespoon of the oil and stir. Add the chicken and season to taste with freshly ground black pepper. At this point, the salad can be completed for serving warm, or the ingredients can be left to cool to serve later.
Just before serving, stir the rocket leaves into the bowl. Mix together the remaining olive oil and the balsamic vinegar, pour over the salad and toss all the ingredients together.
Gently stir in the grapes and chopped mint, then crumble the fetta cheese over the top. Taste and adjust the seasoning if necessary, but the fetta cheese is quite salty so there should be no need to add extra salt.