Step 1

Preheat oven to 400°F (200°C).

Step 2

Bring 2 quarts (litres) of salted water to the boil in a large pot over medium-high heat. Add beans and boil for about 5 minutes.

Step 3

Drain in a colander and quickly immerse beans in a large bowl of ice water to stop the cooking process. Drain and set aside.

Step 4

Melt the butter in a skillet over medium-high heat. Sauté onion for 2 to 3 minutes until softened. Cook garlic until fragrant, about 1 minute.

Step 5

Add mushrooms and cook for 5 minutes. Pour in wine (if using) and allow to cook for 3 minutes.

Step 6

Sprinkle mushrooms with flour, mix well and cook for 2 minutes. Add the broth and simmer for 2 minutes.

Step 7

Reduce heat to medium-low, season with salt, pepper and crumbled bouillon. Stir in the cream or half and half. Cook until the soup thickens (about 4-5 minutes).

Step 8

Remove from the heat and stir in the cooked green beans with half of the onions. Top with the remaining onions.

Step 9

Bake until bubbling, about 15 minutes. Remove and serve immediately.