Heavy olive oil in a large heavy skillet or pan over medium-high heat.
Dry stew beef on paper towels and add to hot oil. Brown on all sides and remove from pan.
Add onion and mushroom to the pan. Saute until softened, about 5 minutes.
Push ingredients to the sides of the pan to make a well in the center. Add garlic to well and saute until fragrant, about 1 minute.
Add beef back to the pan, as well as water and Worcestershire sauce. Bring to simmer, cover and turn heat to low. Simmer for 2½ hours.
Remove from heat and allow to cool slightly.
Stir in 1 cup cream, pepper, and horseradish.
Heat 4 quarts of water to boiling. Add angel hair and cook for 4 minutes or until “al dente”. Drain well but don’t rinse.
Toss pasta with beef mixture and pour into an 8-cup covered casserole dish.
Melt butter in a small saucepan. Stir in flour and bring to simmer, stirring constantly. Stir in the remaining cream and bring back to a simmer, stirring constantly. Remove from heat and add cheeses, stirring until they are melted.
Spread cheese sauce over the top of the beef and pasta mixture. Cover and bake in a preheated 350℉ oven for 20 minutes. Remove cover and bake for 10 minutes or until it reaches an internal temperature of 160℉.
Let the casserole rest for 10 minutes before serving.
Hack: One 4 oz can of mushrooms can replace the fresh mushrooms in this recipe.
Hack: Leftovers can be stored in the refrigerator for up to 5 days. Alternately, seal serving-sized portions in freezer-safe containers and store them in the freezer for up to 3 months.
