In large stock pot over medium high heat, add the vegetable oil and sear off the meat in batches. You are looking for a nice dark brown sear, place the meat in the hot pan and let it sit to sear. Do this in about 3 batches and set aside on a plate.
Add in carrot and onion, sautee for about 3 minutes and add in the garlic. Cook unit the garlic is fragrant about 30 seconds, add the red wine. Scrape any bits off the bottom of the pan with the back of a wooden spoon or something that wont hurt your pan. In a separate bowl, mix the au jus packet with the 3 cups of cold water until the powder dissolves. Add this to the pan with the meat, adding any juices that have run off the meat. Add in the bay leaves and dried thyme to the pot. Cover and bring to a boil, reduce to a simmer and let cook on a simmer for 4 hours until the meat is extremely tender, stirring occasionally. If it gets too dry for your taste add in some water 1/2 cup at a time and taste the broth as you go to make sure it doesn't get too salty. If you need to make the stew thicker to your taste, thicken with a cornstarch slurry (equal parts cornstarch and water whisked together.)
Make the potatoes during the last hour to hour and a half of cook time for the stew. Place the peeled and cubed potatoes into a pan covered with cold water. Boil potatoes until fork tender about 20-30 minutes. Drain off water.
Add in the butter, sour cream and parmigiano. Mash with a potato masher, taste and add salt and pepper to your taste. Set aside.
When the stew is done cooking, stir in the frozen peas, add it to a pie pan and discard the bay leaves. You can also take out the onion petals or leave them in, either way is delicious!
Add the potatoes on top of the stew in dollops and evenly spread out the mash over the whole dish, leaving a 1/2 inch ring around the outside of the pan.
Add a little more parmigiano reggiano on top, about 2 Tbls.
Cook in a preheated 350 degree oven for 30-45 minutes or until the top is a light golden brown and bubbly. To speed up the browning process you can turn on the broiler, but watch it very closely!
Serve on it's own or with biscuits, enjoy!