Heat the oven to 350 degrees.

Grease a baking dish.

Slice the mushrooms and chop the celery and onions.

Cube the bread into 1 inch cubes and place In a large baking sheet.Bake until they're slightly golden and toasted.

In a skillet heat 2 tbsp of butter and add the mushrooms.Cook until they turn slightly golden.

Add the onion and celery and saute for a few minutes.

Add the stock, salt and pepper.Mix well.

Place the toasted bread pieces into a large dish and pour the veggies along with the liquid.Toss to combine.

Pour the mixture into the prepared baking dish and bake for 40 mins.