Sauté the vegetables: In a large pot, heat some oil over medium heat. Add diced onion and cook for 3-4 minutes until softened.

Add carrots and celery: Stir in chopped carrots and celery. Cook for another 5 minutes to let them soften.

Add potatoes and lentils: Add diced potatoes and uncooked lentils to the pot and mix well.

Add water: Pour in enough water to cover the ingredients by 1-2 inches. Vegetable broth can be used for more flavor.

Simmer: Bring the stew to a boil, then reduce to low heat. Let it simmer for 30-40 minutes, stirring occasionally, until lentils and potatoes are tender.

Season to taste: Add salt, pepper, and any extra spices like cumin, garlic powder, or thyme.

Serve: Enjoy your stew as-is or with crusty bread.