Cook quinoa according to package directions. Spread in an even layer on a baking sheet, and let cool.
Spread chickpeas evenly on a baking sheet lined with paper towels. Gently rub chickpeas until dry, removing any skins that peel away. Sprinkle chickpeas with cumin and 1/4 teaspoon of the salt; toss to coat.
Heat 1 tablespoon of the oil in a skillet over medium-low. Add chickpeas; cook, stirring occasionally, until toasted and slightly crisp, 10 to 15 minutes. Transfer to a bowl. 4 While chickpeas cook, whisk together lemon juice, mustard, oregano, pepper, and remaining 1/4 teaspoon salt in a small bowl; drizzle in remaining 4 tablespoons oil while whisking. Combine quinoa, escarole, cucumber, feta, and olives in a large bowl. Add dressing; toss to coat. Divide among 4 bowls; top with toasted chickpeas. Serve immediately.