Beef Shepherd's Pie

1 Tablespoon of olive oil
1 Tablespoon of butter
1 medium onion, diced
3 medium carrots, peeled and diced
1 rib celery
1/2 pound cremini mushrooms(or other mushrooms), cut up
2 cloves of garlic, minced
3/4 teaspoon dried oregano
3 Tablespoons tomato paste or half a can of tomato sauce
1 pound ground beef
1/4 cup beef broth
1 teaspoon worcestershire sauce
Freshly ground black pepper
Salt to taste
3-4 cup mashed potatoes
parmesan or cheddar cheese for the top

Preheat oven to 375 degrees.
Heat the olive oil and butter in a large skillet over medium heat. Add the onion, carrots, celery, mushrooms, garlic, a little salt, and oregano. Cook until vegetables are tender about 10 minutes. Stir in the tomato paste or sauce. and cook until mushrooms are soft, about 8 minutes. Stir in the ground beef, broth, Worcestershire sauce, and some pepper and salt. Cook until meat is no longer pink.
Transfer the meat and vegetables to a 2-quart casserole dish and spread the mashed potatoes over the top. Sprinkle the cheese on top of the mashed potatoes.


Bake until cheese is melted and bubbly, about 40 minutes.