A perfect fall soup recipe

In an unsuccessful but heartfelt attempt to simply force cool, autumnal weather to arrive in Atlanta, my boyfriend and I made this soup for dinner last night. It's got lots of nice fall flavors. The soup is pretty easy. The croutons are more complicated, but (I think) worth it. Now if only fall would get here...

White Bean and Rosemary Soup with Roasted Garlic Croutons

Croutons:
2 whole heads garlic
1/4 c + 2 tsp. olive oil
1 tsp. kosher salt, plus more to taste
1/2 tsp. freshly ground black pepper, plus more to taste
1/2 loaf unsliced whole wheat bread, cut into 1" cubes

Soup:
1 Tbsp. unsalted butter
2 Tbsp. olive oil, plus more for drizzling
1 large onion, chopped (about 2 cups)
2 carrots, peeled and cut crosswise into 1/4" coins
2 stalks celery, cut into 1/4" slices
4 cups chicken or vegetable broth
2 cans (14.5 oz each) white beans, drained, rinsed, and drained again
2 Tbsp. chopped fresh rosemary

1. Preheat oven to 400ºF. Slice off tops of garlic heads so the cloves are just exposed. Rub each head with 1 teaspoon olive oil; wrap loosely in foil. Roast 25 to 35 minutes. Remove from oven (but leave oven on); let garlic cool until comfortable to touch. Squeeze cloves from the heads into a small bowl; mash with a fork and set aside.
2. In a large bowl, combine half the roasted garlic with 1/4 cup olive oil, salt, and pepper. Add bread and toss until well coated. Place bread on a baking sheet and bake 20 minutes, turning once or twice, until golden brown. Remove from oven and set aside.
3. To make soup: In a large saucepan, heat butter and 2 tablespoons olive oil over medium heat. Add onion, carrots and celery, and cook until tender, about 10 minutes. Add broth and remaining half of garlic and bring to a boil; reduce heat and cook 20 minutes, until carrots are very tender. Add drained beans and rosemary; cook 10 more minutes.
4. With an immersion blender or in a food processor fitted with a knife blade, puree half the soup until smooth. Stir to combine. Serve in bowls topped with croutons and drizzled with remaining olive oil.

Makes 4-6 servings.

Recipe developed by Rori Trovato for O magazine.