Tomato Bulgur Soup

Ingredients

• 2 Tablespoons olive oil
• 1 medium onion, finely chopped
• 6 cups chicken broth, preferably low-sodium
• 1 can tomato paste (6 ounces)
• 3/4 cup fine-grain bulgur (see note)
• 1-1 1/2 teaspoons kosher salt
• 1 teaspoon freshly ground black pepper
• Pinch of Aleppo or other spicy red pepper, optional
• 3 Tablespoons fresh lemon juice, more to taste
• Finely chopped fresh parsley