Add 3 tbsp of olive oil to a heavy-bottomed pot and turn to medium heat. When oil is hot, add onions, carrots, and celery and cook for 10-15 minutes or until translucent. Add garlic and red pepper flakes, and cook for an additional 3-5 minutes.
Add vegetable stock, lentils, crushed tomatoes, bay leaves, paprika, and salt. Bring to a boil. Reduce to a low simmer, cover loosely, and cook for 30 minutes.
Remove bay leaves and pulse soup for 3-5 seconds using a stick blender. Simmer for an additional 20 minutes.
Mix in al dente pasta, and cook for additional 1-2 minutes or until desired tenderness.
Serve with a fresh parsley sprig garnish.