Heat olive oil in a medium pot. Add garlic and onions and sauté until fragrant; then add celery and continue to cook until celery begins to soften, about 10 minutes. Add the stock and adjust the heat to a simmer. Let the celery simmer for about 20 minutes, or until soft.
Preheat oven to 375 degrees. Spread torn bread on a baking sheet, drizzle with olive oil and season with salt and pepper; then place in the oven and bake until golden brown and crunchy. Remove soup from heat and let slightly cool; then transfer to a blender and pulse until smooth. Return soup to the pot and bring to a low simmer; then stir in heavy cream or coconut cream and season with salt and pepper to taste. Top with crunchy croutons and serve.