Preheat the oven to 400°F and grab 2 large rimmed baking sheets. Line them with parchment paper for easier cleanup.
Add the tomatoes, carrots, red bell pepper, onion, and garlic cloves to a large mixing bowl. Drizzle with the oil and season with the salt and black pepper.
Spread the vegetables on the prepared baking pan and roast for 45-50 minutes, stirring the vegetables halfway through, or until the carrots are fork-tender and the tomatoes are blistered. Remove from the oven and cool at room temperature for 1-2 hours until cool to the touch (or cool in the refrigerator for about an hour).
Add the cooled vegetables, cucumber, olive oil, red wine vinegar, and ground cumin to a high-speed blender or food processor. Blend for 1-2 minutes or until smooth.
If the soup is too thick for your liking, blend in water by the tablespoon until your desired consistency.
For an ultra-smooth soup, press the mixture through a fine mesh sieve. Cover the soup and refrigerate for at least 2 hours and up to 24 hours.
Before serving, season the soup to taste with salt and pepper. Enjoy cold, topped with your favorite toppings.