Heat oil in a large quart pot over medium heat. Add the onion and cook until translucent, about 2-3 minutes. Add the rest of the vegetables and cook for 5 minutes, stirring occasionally.
Add tomato paste and Italian seasoning and stir until well-incorporated.
Add the tomatoes, water, and lentils, stir and bring to a boil. Reduce heat to low, cover, and cook for 25-30 minutes, stirring occasionally.
In the meanwhile, place a pot of water on the stove, bring to a boil, and cook pasta. Set aside.
Once sauce has cooled, transfer to a blender and blend until smooth. You can also keep it chunky depending on your preference.
Notes
Serving suggestions
For beginner eaters, puree the sauce. It will stick nicely to the pasta and be easier for baby to eat. Serve a small portion at a time as seeing too much food can be overwhelming.
For older babies and toddlers, skip the extra step of blending. It will be great texture exposure.
For older children and adults, you can season with salt and add some cheese. Small amounts are fine for babies and toddlers. You just want to watch their sodium intake.
Storage suggestionsThis recipe makes a lot. I recommend freezing in food storage trays. Once frozen, pop them out and transfer to a freezer-safe bag/container. Will keep for 3 months.