Preheat the oven to 350 degrees Fahrenheit.
Chop the bell peppers, peel and chop the carrots and chop the red onion.
Add to a baking sheet lined with parchment paper and drizzle with one tablespoon of the oil.
Roast for 40 minutes.
Bring a large pot of water to a boil and cook pasta according to package instructions.
Meanwhile, saute the minced garlic in a pot with the remaining tablespoon of oil.
When the veggies are done, add to a blender with the milk, salt, pepper, red pepper flakes and tomato paste.
Blend until completely smooth.
Transfer to the pot with the garlic and stir in the parmesan.
Whisk together and heat over low heat.
Combine with the cooked pasta, taste and adjust flavors as desired. I often add more red pepper flakes for spice, more salt or more parmesan.
Serve warm and enjoy!