Wash and dry all fresh produce. Thinly slice celery, core and slice green apples into matchstick pieces, cut cucumber into 1/4-inch half-moons, and finely chop red onion and fresh dill.

In a small mixing bowl, combine lemon juice and zest with olive oil. Whisk in sea salt, sugar if using, and black pepper until emulsified.

Combine all prepared vegetables in a large mixing bowl and toss gently.

Pour dressing over combined vegetables and toss gently to coat.

Serve immediately or refrigerate for up to 30 minutes to chill.