Heat the olive oil in a large pot over medium heat. Add the onion, celery, garlic, paprika, coriander, cumin, turmeric, ½ teaspoon salt, and pepper. Cook for 10 minutes, stirring occasionally, until the vegetables are softened.
Stir in the vegetable broth, crushed tomatoes, chickpeas, and lentils. Bring to a boil, then reduce the heat to a simmer and continue cooking for 30 minutes, stirring occasionally.
Stir in vermicelli and remaining 1 teaspoon salt, and cook until tender, 10 to 15 minutes.
Stir in the chopped parsley and lemon juice and serve.
