• 2 Tbsp unsalted butter
• 1 lb cremini mushrooms - sliced 1/4“ thick
• 8 oz. shitake mushrooms - stems trimmed, caps sliced 1/4”
• 2 onions - minced (~2 cups)
• 4 med garlic cloves minced (~4 tsp)
• 2 Tbsp chopped fresh thyme leaves or 2 tsp dried
• 2 1/2 tsp salt
• 1/2 tsp ground black pepper
• 5 lb russet potatoes (about 10 med) peeled and sliced into 1/8“ thick with food processor
• 1-15oz. low-sodium chicken broth
• 1 3/4 cup half and half
• 1 Tbsp corn starch - mixed in cold milk
• 4 bay leaves
• 8 oz cheddar cheese shredded

1. Heat oven to 425 deg with oven rack in middle position
2. Melt butter in 8 qut stock pot until foaming subsides. Add mushrooms and onions and cook, stirring occasionally, until soft and lightly browned and mushrooms have released moisture, about 5 min. Add garlic, thyme, salt, and pepper; cook until fragrant, about 30 sec. Add potatoes, chicken broth, cream, corn starch blended in milk and bay leaves and bring to simmer.
3. Simmer covered until potatoes are almost tender(paring knife in and out with some resistance), about 15 min. Discard bay leaves.
4. Transfer mixture to 13×9 stainless baking pan. If desired pan can be covered with foil and stored prior to cooking in the oven. If so provide additional initial bake time covered with foil.
5. Bake in 425 deg oven for 10 min.
6. Remove pan from oven and sprinkle evenly with cheese. Bake for an additional 15 min. until bubbling around edges and top is golden brown.
7. Cool 15 min before serving.
8. Half size batch reduce quantity by 2 and bake in 8×8 baking dish.

Serves: 12      Total cook time: 1 hour; 20 min pot; 25 min oven, 15 min rest
Source: Cook's Illustrated March/April 2003