Preheat a large soup pot over medium heat. Saute the onions until translucent, 5-7 minutes. Add the garlic, herbs, salt, and pepper. Saute for 1 more minute, until garlic is fragrant.
Add the potatoes and sun-dried tomatoes. Pour in the water. Cover and bring to a boil. Once the soup is boiling, lower the heat to medium, cover, and let simmer for about 20 minutes, until the potatoes are tender and the sun-dried tomatoes are soft.
Add the crushed tomatoes and heat through. If you have an immersion blender, you're in luck! Puree the living hell out of it until it is very smooth. If you don't have one just transfer the whole shebang to a food processor or blender, in cooled batches, then transfer back to the pot. Add the lemon juice and adjust the salt if you need to.
Variation: add half cup of shredded basil after pureeing.