Thinly slice the red onion and place it in a large mixing bowl. Drizzle with lemon juice and zest, sprinkle with salt, and let it sit for 15 minutes.

Drain and rinse the butter beans and chickpeas. Chop the olives and artichokes, then add them to the bowl with the onions.

In a small skillet, heat one tablespoon of olive oil over medium heat. Sauté minced garlic until golden brown, then remove from heat and stir in za’atar and sumac.

Pour the warm marinade over the bean and vegetable mixture. Toss gently to coat all ingredients.

Let the salad sit at room temperature for at least 2 hours or refrigerate for several hours to enhance the flavors.