Cut the tomatoes and onion into quarters.
Place the tomatoes, onion, and peeled whole garlic on a lined baking sheet. Drizzle with olive oil and add the salt, pepper, oregano, and Italian seasoning.
Toss to fully coat and bake at 375 degrees for 45 minutes.
In a large pot, add the chicken stock and basil, then bring to a simmer.
Add in the vegetables and simmer for 2 minutes.
Remove from heat and use a stick blender until smooth.
Stir in the heavy cream and garnish with fresh basil.
