Middle Eastern Bean Salad

Ingredients

• 1/4 cup extra-virgin olive oil
• 3 tablespoons freshly squeezed lemon juice
• 1 1/2 teaspoons minced garlic, or to taste
• sea salt to taste
• freshly ground black pepper to taste
• 1 bunch flat-leaf parsley, chopped
• 1 (15 ounce) can light red kidney beans, drained and rinsed
• 1 (15 ounce) can garbanzo beans, drained and rinsed
• 1 cup minced red onion, or to taste
• 1 pinch ground sumac, or to taste (optional)