Rinse the bulgur wheat under cold water. In a medium saucepan, combine bulgur with water. Bring to a boil, then simmer for 10-15 minutes until tender and water is absorbed. Fluff with a fork and let cool.

In a large mixing bowl, add the drained chickpeas, diced cucumber, and chopped onion. Add parsley and mint, and mix gently.

Once cooled, add bulgur to the mixing bowl. Crumble feta cheese and add pistachios, then fold gently together.

In a mason jar, combine lemon juice, olive oil, and mustard. Season with salt and pepper, then shake well to emulsify.

Pour the dressing over the salad and toss gently to coat. Cover and refrigerate for at least 1 hour.

Before serving, give the salad a light toss and garnish with a squeeze of lemon juice if desired.