In a Dutch oven or large pot, heat the olive oil over medium heat and cook onions, about 5 minutes. Add the minced garlic and cook another minute.
Stir in the lentils, rice, carrot, Lebanese Seven Spice blend, turmeric, salt and pepper, and cook until the spices are fragrant, about 2-3 minutes.
Add 8 cups of water, and bring to a boil. Turn heat to low and cook covered until the rice and lentils are fully cooked, about 20 minutes.
Stir in the lemon juice. Serve whole or using an immersion blender, pulse a few times for desired consistency. Garnish with green onions, parsley, lemon slice and serve warm with pita or bread of choice.
I oftentimes add shredded rotisserie chicken before simmering the soup in Step 3, to create a heartier meal.