1. Wash and soak the green lentils for 8 to 10 hours or overnight. Once soaked, drain the water and rinse the lentils. Transfer them to a pot, add salt and water. Cook over medium-high heat and bring to a vigorous boil. Reduce the heat to medium-low and cook for about 4 minutes, or until the lentils are cooked but still hold their shape. Do not overcook; we want firm lentils. Immediately strain the cooked lentils and let them sit in the strainer to remove excess water and cool down.

2. Once the lentils have cooled, add lemon juice, olive oil, and mix well. Allow the lentils to marinate while continuing with the rest of the cooking.

3. In a separate pot, heat olive oil over medium heat. Add onions, carrots, and garlic. Sauté until the onions become translucent and the carrots soften slightly.

4. Add tomato paste, paprika, ground cumin, cayenne pepper (if using), and salt. Stir well to coat the vegetables with the spices.

5. Add the soaked and drained quinoa to the pot and stir to combine with the vegetables and spices.

6. Pour in the vegetable broth and bring to a boil. Reduce the heat to low, cover the pot, and simmer for about 15 minutes, or until the quinoa is cooked and the liquid is absorbed.

7. Remove the pot from the heat and let it sit, covered, for 5 minutes. Fluff the quinoa with a fork.

8. Add the marinated lentils to the cooked quinoa and gently mix to combine.

9. In a separate bowl, combine the chopped red onion, parsley, mint, and ground black pepper. This will be used for garnishing the salad.

10. Serve the quinoa and lentil salad in individual bowls or plates, and sprinkle the garnish mixture on top.

11. Enjoy the flavorful and nutritious quinoa and lentil salad!

Note: The calorie count will depend on the specific brands of ingredients used. Please refer to the nutritional information on the packaging of the ingredients for a more accurate calorie count.