1 spaghetti squash, halved lengthwise and seeded
6 tablespoons extra-virgin olive oil, plus extra for drizzling
salt and pepper
2 teaspoons grated lemon zest plus 7 teaspoons juice
1 (15-ounce) can chickpeas, rinsed
2 ounces feta cheese, crumbled (½ cup)
½ cup coarsely chopped fresh parsley
4 scallions, sliced thin on bias
2 tablespoons chopped toasted pistachios or pine nuts