Heat the extra virgin olive oil in a large heavy-bottomed pot or Dutch oven over medium heat.
Add the diced onion, carrots, and celery to the pot and sauté for 8 minutes until the vegetables are softened and translucent.
Stir in the minced garlic and cook for 60 seconds until fragrant, ensuring the garlic does not burn.
Add the rinsed lentils, diced tomatoes with their liquid, vegetable broth, oregano, basil, and red pepper flakes to the pot.
Bring the mixture to a rolling boil, then reduce the heat to low, cover the pot, and simmer for 25 minutes.
Remove the lid and stir in the ditalini pasta; continue to simmer uncovered for 10 to 12 minutes until the pasta and lentils are tender.
Stir in the chopped spinach and lemon juice, cooking for 2 minutes until the greens have fully wilted.
Season the soup with salt and black pepper to taste.
Ladle into bowls and serve immediately, garnished with grated parmesan cheese.