Heat oil, then saute onions on medium-high heat for five minutes in a medium-sized pot.
Add celery to the onions and cook for five minutes, then add carrots, then cook for another five minutes.
Make a hole in your onion mixture then add the garlic and cook just until fragrant, about 30 seconds to 1 minute. Stir the garlic into the rest of the veggies so it doesn't burn.
Add the black pepper, salt, thyme, cumin, and curry powder. Let the spices toast with the veggies for 30 seconds.
Add the diced tomatoes, chicken broth, and a can of tomato sauce. Bring the soup to a simmer and cook covered for 10 minutes.
While the soup is simmering, rinse the lentils - pick out any bad ones, then add them to the soup. Cook the lentils for 30 minutes or until tender. Add more broth as needed.
Add the mixed veggies and cook for another 5 - 10 minutes.
Serve the soup while it's hot.
Notes
The soup keeps in the refrigerator for about 3 - 4 days.
All nutrition information is automatically generated and should be only used as a rough estimate. This recipe card may contain affiliate links.