Preheat oven to 425°F.
1. Pierce potatoes in several places to allow steam to escape. Place potatoes on oven rack or baking sheet. Bake 40 to 55 minutes or until tender when pierced with a fork. (Or microwave potatoes on high for 5 to 9 minutes each.)
2. Meanwhile, spray a large saucepan with nonstick cooking spray. Place saucepan over medium-high heat and add olive oil. When hot, add onion, garlic, and celery and sauté for 2 to 3 minutes.
3. Add the mushrooms, water, lentils, tomato paste, carrots, cumin, curry powder, onion powder, and salt.
4. Bring to a boil. Cover and reduce heat to simmer. Cook for 40 to 45 minutes or until lentils are tender.
5. To serve, cut the baked potatoes in half and top with the seasoned lentil mixture.
Makes 4 servings.