Half and pit the tomatoes, scooping out most of the extra seeds and juices.
Spread tomatoes in a shallow pan and coat with ¼ cup olive oil. Sprinkle with salt and pepper.
Roast tomatoes for 40 minutes, turning halfway through.
While tomatoes are roasting, place 3 tablespoons of olive oil, garlic, red pepper flakes, and diced onion in a large cooking pot or Dutch oven.
Saute over medium-low heat until garlic is fragrant and onion is tender and beginning to caramelize (4-5 minutes).
Add wine and dried thyme. Saute 2-3 minutes longer.
Pour roasted tomatoes (including skins and juices) into the cooking pot. Add canned tomatoes, fresh basil, and 4 cups of water.
Bring soup to a boil. Reduce heat to low and simmer for 40-50 minutes (or longer), covered.
Remove soup from heat. Puree with an immersion blender or transfer in batches to a countertop blender and blend. (Be careful the hot soup does not splatter).
Add heavy cream to taste and serve immediately.
Add chives, bacon, and/or croutons when serving. You can also drizzle a bit more heavy cream into the bowl of soup.
Notes
Tomato bisque can be stored in an airtight container in the refrigerator for 3-5 days. You can make the soup ahead of time - do not add cream until you've reheated it and are ready to serve.*Nutrition information does not include calculations for toppings.