Preheat the oven to 425 degrees and line a baking dish with parchment paper.
Add the veggies, oil & dry seasonings to the baking dish and toss to coat. Place in the oven for 20 minutes. Toss and place back in the oven for 10-20 minutes, or until the veggies are tender. Remove from the oven and allow to cool slightly.
Transfer the veggies (and all of their liquids) to a food processor and blend. You can leave this as chunky or smooth as you want.
Transfer the veggie mixture to a stock pot and add the jar of marinara. Cook over low heat until heated through. Taste and adjust the seasonings as needed. Serve over your favorite pasta.
Video
Notes
The texture of this sauce is meant to be a little chunky. If you want it to be smooth, I would use a blender instead of a food processor.
Adjust the veggies to what you have on hand - you could even sneak in some spinach or cauliflower!
To make this baby-friendly: adjust the seasonings when roasting (if omitting salt from your baby's diet), blend and serve with pasta. We're basically omitting the jar of marinara. I also pulsed some cooked spaghetti with his.