Preheat your oven to 400℉ and line a large baking sheet with parchment paper.
To prep the veggies, cut just the tops off of the squash, cut the top off of a bulb of garlic, chop the carrots into large pieces and cut the onion into 6 equal parts.
On a baking sheet, add the squash, carrots, garlic (wrapped in foil with the cut top portion exposed), and onion and drizzle with olive oil. Sprinkle salt and pepper over the top, toss to coat evenly and then spread everything out on the pan.
Bake the veggies in the oven for 30 minutes.
Once the veggies are done, scoop 2 cups worth of the squash out and remove the garlic from its husk. Now, all that's left to do is blend everything together with broth and herbs. You'll want to do this in two batches.
Take half of the roasted veggies and blend them with 1-1 ½ cups of broth and half of the herbs until completely smooth. Pour the blender contents into a pot on the stove to keep warm while you blend the second half of the veggies and another 1-½ cups of broth and the other half of the herbs.
Pour the second batch of the blender contents into the pot to keep warm and enjoy!
If you'd like, you can top with grated parmesan cheese and a crack of black pepper.