In a large pot over medium heat, saute 3 small yellow onions, 2 celery sticks, 4 small carrots, head of cauliflower, in 2 tbsp olive oil, until tender - about 5 minutes
Add garlic and saute for another minute
Add 1 can of crushed tomatoes, 1 tbsp balsamic vinegar, 1 tsp tomato paste, 2 tbsp Italian seasoning, and 1 cup of red lentils to the pot and stir to combine.
Add 5 cups of water (or broth), or until everything in the pot is covered.
Bring to a boil, then reduce to simmer for 45 minutes, stirring occasionally.
Puree with an immersion blender and serve.