Tie herbs together with kitchen twine.
Season beef with salt & pepper.
In a large Dutch oven, heat 1 tbsp of olive oil over medium high heat.
Working in batches, add the beef to the Dutch oven & sear until the outside is lightly browned (about 10 minutes per side).
Transfer beef to plate. Add another tablespoon of oil & sear remaining meat. Transfer to plate with the rest of the beef.
Add carrot, onion halves to Dutch oven & cook until lightly browned.
Stir in garlic & cook until fragrant.
Place cooked garlic, onion, & carrots into a slow cooker.
Add beef stock, Stout, herbs, steak sauce, fish sauce, soy sauce, & worcestershire sauce to the slow cooker.
Cut beef into 1 inch pieces & transfer to a big mixing bowl.
Add flour & stir until the beef is evenly coated.
Add beef to the slow cooker.
Cook on low for 8 hours.
Remove carrots, onions, & herbs & discard.
Place stew in a large pot & heat over medium heat on the stovetop.
Whisk together cornstarch & 1/4 cold beef stock. Stir into the stew. Cook on medium while stirring until the sauce thickens (about 5 minutes).
Meanwhile, toss the diced carrots in 1 tablespoon oil and 1/4 teaspoon salt & pepper to taste. Roast for 20-25 minutes at 350° F.
Blanch the peas by placing them in a medium pot of boiling water. Allow them to boil for 1 minute, then drain & immerse them into a bowl of ice water. Drain.
Stir the carrots & peas into the stew.
Allow the stew to cool completely before assembling the pies.