Preheat the oven to 170°C. Line two baking trays with baking paper.
Place the tomatoes and capsicums on the baking trays, drizzle with half the olive oil and season with salt and pepper blend. Roast for an hour or until the capsicum is tender. Peel the skin from capsicum once cooked.
Meanwhile prepare red lentils. Before cooking, follow on pack instructions to rinse and pick over any lentils. In a medium pot, add lentils and 3 cups of water, bring to a boil, then lower heat and simmer gently for 10 minutes. Drain.
Heat the remaining olive oil in a heavy saucepan over medium heat, add onion and curry powder and cook for 3 minutes or until the onion is translucent. Add the paprika, cumin and celery and cook for 5-7 minutes or until celery is tender, then add garlic and cook for another 1-2 minutes.
Stir in the tinned tomatoes and cook for a further 8-10 minutes. Stirring occasionally.
Remove the pan from the heat. Add the roasted tomatoes, capsicum and cooked Red Lentils. Use a hand-held blender to puree until smooth. Return the pan to a low to medium heat. Add stock, season to taste and cook for a further 15 minutes. Serve hot and garnish with natural yoghurt and some finely chopped basil.