Creating this Savory Bread Pudding with Mushrooms and Gruyere Cheese is straightforward if you follow these simple steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking dish.
2. Sauté Vegetables: In a skillet over medium heat, add olive oil. Sauté the diced onion and minced garlic until translucent. Add the sliced mushrooms and cook until they are tender and browned. Stir in the thyme, salt, and pepper. Remove from heat and let cool slightly.
3. Prepare Bread: In a large bowl, combine the cubed bread and the sautéed mushroom mixture. Toss gently to combine.
4. Mix Wet Ingredients: In another bowl, whisk together the eggs, milk, and heavy cream until well mixed. Season with a pinch of salt and pepper.
5. Combine Mixtures: Pour the egg mixture over the bread mixture. Gently stir until the bread is well coated and soaked.
6. Add Cheese: Fold in the grated Gruyere cheese, reserving a little for topping.
7. Transfer to Baking Dish: Transfer the mixture to the prepared baking dish, spreading it evenly. Sprinkle the reserved cheese on top.
8. Bake: Place the dish in the oven and bake for 40-45 minutes, or until the top is golden brown and a knife inserted into the center comes out clean.
9. Cool: Once baked, remove from the oven and let it cool for a few minutes before serving.

These steps will guide you in creating this incredible Savory Bread Pudding effortlessly.