Slice the onions into wedges or chunks. Heat the olive oil in a large pot and add the onions. Sauté for about 2 minutes. Crush, slice, or mince the garlic and add it to the pot. Chop the carrots into small pieces (about ½-inch cubes or smaller), and add to the pot. Sauté the vegetables together for about 5 minutes.
Add the canned tomatoes and about half of the basil (¼ cup only). Simmer the soup for about 20 minutes, or until the carrots are soft. Remove from heat and add to your blender. (Or blend with an immersion stick.) Blend until smooth and return to the pot. Add the milk, the salt, and the remaining basil. Bring to a simmer and then immediately remove from heat. Serve immediately or freeze for later. Pair with crusty bread, whole wheat naan, cheddar garlic biscuits, or grilled cheese. :) Top with parmesan cheese, basil, or pesto!
Notes
This serves two adults as the main meal or four adults as a side. (Paired with salad, pizza, or grilled cheese.)