In a large pot, heat up one tablespoon of olive oil over medium heat. Add the chopped celery, onion, and carrot to the pot and sauté for 5-8 minutes, or until transparent.
Next, add the chopped tomatoes to the cooked vegetable mixture. Cook the tomatoes for 3-4 minutes, or until they start to soften. 30 seconds later, add the garlic and stir until fragrant.
Add the rinsed lentils, bay leaf, and vegetable stock to the pot. Bring the soup to a boil. Then cover with a lid and reduce the heat to a simmer (low heat) for 20-25 minutes or until lentils are nice and tender.
In addition, add the cumin, coriander and oregano, cumin along with a little more salt and pepper. Make sure to taste once the lentils have cooked through. For another five minutes or so, simmer the soup on low, uncovered, to allow the flavours to blend.
Lastly, top the soup with lime wedges. Garnish it with diced avocado, tomatoes, green onions, or fresh cilantro.