When Senator Harkin makes soup he doesn't add any salt, so this local low-sodium roasted tomato soup recipe is for him. It's great September soup, for when the tomatoes are extremely ripe and juicy. We use lovage, a strong herb reminiscent of celery, as a garnish that adds a lot of flavor.

2 tablespoons butter
4 lbs tomatoes, about 8 medium sized tomatoes, stems removed
¼ cup small sweet onions, medium dice
2 cloves garlic, smashed
2 tablespoons rolled oats
A few sprigs of thyme
A small glug of half and half (optional)
Scant handful of lovage, finely chopped

Roast the tomatoes in a buttered baking dish at 375ºF for 1 hour.
Sweat the onion and garlic in the rest of the butter until translucent and soft.
When the tomatoes are fragrant and cooked through, remove them from the oven, and transfer to a sieve-lined bowl. Use tongs to break up the tomatoes and release the juices, allowing the juices to fall through the sieve. Transfer the tomato pieces to the pot with the sweating onion, and simmer for a few minutes. Pour over the reserved juices from the bowl. Add about 1 cup of water, or just enough to cover the fruit. Bring to a simmer and add the oats and thyme. Simmer until the contents have thickened.
Remove the thyme, blend the soup, and strain back into the pot.
Bring to a simmer again and reduce until you have reached the desired consistency. Season with salt to taste, and pour in the half and half (if using).
Divide the soup amongst the bowls and garnish with the lovage.