1. Preheat the oven to 400°F. Drain and rinse the chickpeas and mix with the chili powder, oil, a pinch of salt and a few grinds of black pepper. Spread evenly on a baking tray and roast for 30 minutes, gently shaking the tray every 10 minutes.
2. While the chickpeas roast, cut the avocado in half lengthwise. Remove the pit, scoop out the flesh with a spoon and place in food processor (a mini food processor works well here). Cut the jalapeño in half lengthwise, remove the seeds with the tip of a knife and roughly chop. Roughly chop the green onions. Remove the leaves from the mint sprigs. Add half the jalapeño, all of the green onions, half of the mint, 2 tbsp lime juice and 3 tbsp water to avocado and purée. Season the guacamole with salt (in moderation), pepper and more lime juice if desired. Store covered in the refrigerator.
3. Cut the cucumber lengthwise, remove the seeds with a teaspoon and cut into cubes. Thinly slice the remaining mint leaves and finely dice the remaining jalapeño and toss with the cucumber. Season to taste with salt (in moderation) and pepper.
4. To assemble, top each tortilla with a lettuce leaf, guacamole, cucumber salsa, chickpeas and crumbled feta.
Per serving: 311 calories, 19g fat, 7g saturated fat, 33mg cholesterol, 737mg sodium, 26g carbohydrate, 10g fiber, 4g sugar, 13g protein