Preheat the oven to 450°. Put tomatoes, garlic, and onion in a Dutch oven (see note 4). Toss with the canola oil, salt, and pepper until combined and evenly coated.
3 lbs tomatoes, 8 cloves garlic, 1/2 yellow or white onion, 2-3 Tbsp canola oil, 1/2 tsp black pepper, 1 tsp salt
Put the Dutch oven in the preheated oven for 35 minutes.
After removing from the oven, add chicken stock, butter, and sugar to the Dutch oven. Blend until smooth with an immersion blender (see note 5) or carefully with a blender.
1/2 cup chicken stock, 1 Tbsp sugar, 2 Tbsp butter
Slowly add heavy cream to the pot and stir until well combined. Serve soup immediately, topped with fresh basil.
1/2 cup heavy cream, 1/2 cup fresh basil