1. Peel the onion and garlic, then chop them finely.

2. Sauté the onion and garlic in about 25 grams or 2 tablespoons of butter until they soften.

3. Add 1 teaspoon of garam masala powder and 0.5 teaspoons of paprika powder to the pan. Cook for 1 minute, allowing the spices to infuse.

4. Next, add 250 milliliters or 1 cup of tomato puree, 125 grams or 1/2 cup of lentils, 2-3 diced potatoes (about 250 grams or 8.8 ounces), and 500 milliliters or 2 cups of vegetable broth to the pot.

5. Bring the mixture to a boil at 100°C or 212°F. Then, reduce the heat to a simmer at around 85-90°C or 185-194°F. Let it cook for about 15 minutes, or until the potatoes and lentils are tender.

6. Season the soup with salt and black pepper to taste.

7. Warm the naan bread according to the package instructions. You can usually do this by wrapping it in a damp cloth and heating it in the microwave for 20-30 seconds.

8. Serve the soup hot, accompanied by the warm naan bread and topped with a dollop of yogurt.

9. Garnish with a sprinkle of cumin powder if desired.