Place beef shanks in a slow cooker. Pour 1/2 c. water over shanks and sprinkle with packet of soup mix.
Set slow cooker on low for 8 hours.
After shanks are cooked, remove bones and any large chunks of fat from slow cooker. Shred meat with a fork.
In a Dutch oven or stock pot, add 1 Tbsp. olive oil.
Add diced onions and garlic to pot and cook until onions are soft.
While the onions are cooking, preheat the oven to 425 degrees.
Unroll one pie crust into the bottom of pie pan and set aside.
After onions are cooked, add 3 Tbsp. butter to pot and melt.
Add 3 Tbsp. flour to the pot. Stir and cook for about 1 minute.
Add shredded meat and juices from the slow cooker to the pot and stir together.
Add thyme, rosemary and Worcestershire sauce. Cook, stirring periodically until sauce thickens.
Stir in the bag of peas and carrots and cook a few more minutes.
Place the meat mixture into the pie pan lined with the pie crust.
Roll out the other pie crust on top of the meat mixture. Pinch the edges together and cut a slit in the middle of the pie.
Put the pie in the oven and bake 30-40 minutes or until the crust is a golden brown. You may want to cover the edges with strips of foil during the last 15-20 minutes to prevent the edges from getting too brown.
Let stand about 5 minutes before serving