Rinse 1 cup lentils and sort out any debris
Heat 1 tablespoon oil in a pot over medium heat
Add 1 chopped onion and cook until soft
Add 2 chopped carrots and 2 chopped celery stalks
Add 2 minced garlic cloves and cook for 1 minute
Stir in 1 teaspoon salt, 1/2 teaspoon black pepper, 1 teaspoon cumin, and 1/2 teaspoon turmeric
Add the rinsed lentils
Pour in 6 cups vegetable or chicken broth
Add 1 bay leaf if desired
Bring to a boil
Reduce heat and simmer for 25 to 35 minutes until lentils are tender
Stir occasionally and add more broth or water if needed
Remove the bay leaf
Add lemon juice to taste
Adjust seasoning with salt and pepper
Serve hot