Step 1 Preheat oven to 180°C. Bake chicken, in a cooktop-safe baking dish, for 10 minutes. Add mushrooms. Bake for 15-20 minutes or until chicken is tender. Cut chicken into slices. Set aside.
Step 2 Meanwhile, cook pasta in a pot of salted boiling water according to packet directions. Add asparagus in last 3 minutes of cooking. Drain. Set aside.
Step 3 Heat same baking dish on cooktop over medium heat. Add garlic and breadcrumbs. Cook, stirring, until crumbs are lightly browned. Pour into a bowl, cover.
Step 4 In a large pot, bring stock to the boil. Reduce heat. Simmer for 5 minutes or until reduced. Add evaporated milk, spaghetti, mushrooms, asparagus and chicken. Stir until well combined. Serve topped with crumb mixture.