Preheat oven to 300 degrees.
Place a heavy-bottomed Dutch oven over medium-high heat and add 2 tablespoons bacon fat and 1 tablespoon grapeseed oil. While the oil heat, pat 2 pounds venison stew meat dry with a paper towel. Add to the preheated oil. Sprinkle 1 tablespoon Kosher salt, 1 tsp. onion powder, 1 tsp. garlic powder, 1 tsp. dried oregano, ½ tsp. smoked paprika, and ½ tsp. black pepper over the meat, stirring to coat.
Cook the venison, stirring once or twice, until the pieces have browned, about 8 minutes. Deglaze the pan with 12 ounces of brown ale. Be sure to scrape the pot to get all the delicious, browned bits off the bottom. Add the sliced onion, garlic cloves, 1 tablespoon Worcestershire sauce, and 3 cups of beef stock. Stirring to combine.
Tie the rosemary and thyme sprigs together with butcher’s twine before nestling into the cooking liquid, followed by the bay leaf.
Cover pot and cook stew in preheated oven for 1 ½ hours. Remove from oven and stir in 1 pound baby carrots and 1 pound diced red potatoes.
Return to oven and cook for one more hour. Remove stew from oven, taste, and adjust seasoning. Remove the bay leaf and herb bundle and discard. Whisk ½ cup of the cooking liquid with 1 tablespoon cornstarch and return to the pot. Stir in the peas.
Once liquid has thickened slightly, stew is ready to serve!