LEEK AND ONION SOUP

5 tablespoons olive oil
3 large leeks (white and pale green parts only), sliced
1 1/2 pounds russet potatoes, peeled, diced
1 large white onion, chopped
4 141/2-ounce cans vegetable broth
3 large garlic cloves, chopped
1 1/2 cups grated Swiss cheese
8 slices sourdough bread
1/2 cup chopped fresh chives or green onion tops

Heat 4 tablespoons oil in heavy large pot over medium-low heat.
Add leeks, potatoes and onion.
Sauté until onion is tender, stirring occasionally, about 12 minutes.

Add broth and bring soup to boil.
Reduce heat to medium-low.
Simmer until all vegetables are tender, about 20 minutes.

Working in batches, puree 5 cups soup in blender.
Return puree to soup in pot.
Season with salt and pepper. (Can be made one day ahead. Refrigerate uncovered until cold, then cover and keep refrigerated.)

Preheat oven to 350° F.
Stir remaining 1 tablespoon oil and garlic in small skillet over low heat until garlic is fragrant, about 1 minute; remove from heat and cool.
Add cheese to garlic in skillet; toss to combine.

Arrange bread slices on baking sheet.
Spoon cheese mixture onto bread slices, dividing equally.
Bake toasts until cheese melts, about 10 minutes.

Bring soup to simmer over medium heat, stirring frequently.
Ladle into bowls.
Sprinkle generously with chives.

Serve, passing toasts separately.
— Source: www.epicurious.com.