Heat oil in a sauce pan. Cook onion and carrots, until tender. Add beef, keep stirring until cooked. Stir in rosemary, thyme, paste, and sauce for 2 minutes. Add in stock, brown sugar, and blended flour. Keep stirring until the mixture thickens and the sauce has reduced. Pour mixture into dish.
Spread mashed potato on top of the beef mixture.
Add cheese on top **optional
Bake in oven for 20 minutes or until the topping is golden.
POTATO TOPPING
Boil potatoes until tender; drain.
Mash with pepper, salt, butter, and milk until smooth. Cool; stir in egg yolk.
Recipe by One Chopping Board at https://onechoppingboard.com/cottage-pie/