Cream of asparagus soup

Ingredients

• 1 tablespoon olive oil
• 1 onion chopped
• 3 celery stalks chopped
• 1 garlic clove minced
• 1 pound asparagus (tough ends removed and discarded) chopped (about 4 cups)
• 4 cups vegetable broth
• 1/3 cup soft silken tofu crumbled
• salt and freshly ground pepper to taste