Watercress Soup with Toasted Croutons

Preheat oven to 375°F (190°C).

In a large pot, heat olive oil over medium heat. Add onion and cook until softened, about 5 minutes.

Add diced potato and vegetable broth to the pot. Bring to a boil, then reduce heat and simmer for 15 minutes, or until the potato is tender.

Add watercress to the pot and cook for 2-3 minutes, until wilted.

Carefully transfer the soup to a blender (or use an immersion blender) and blend until smooth.

Return the soup to the pot. Stir in heavy cream (if using) and season with salt and pepper to taste. Heat through.

While the soup is simmering, prepare the croutons: Toss bread cubes with olive oil, minced garlic, salt, and pepper. Spread on a baking sheet.

Bake the croutons for 8-10 minutes, or until golden brown and crispy.

Serve the soup hot, garnished with toasted croutons.