Lots of prep work here. Dice onions and celery. Cut beef into bite-sized pieces. Peel the parsnips, carrots and potatoes and cube into similarly-sized chunks.
Add onions and celery to a pan with a drizzle of olive oil over medium heat until fragrant (2-3 minutes).
Add beef to the pan and brown, turning so each piece is cooked on all sides. Add thyme, parsley, oregano, salt and pepper. Measure those with your heart - I just did a big sprinkle of each. Add tomato paste and stir to coat beef - cook for 4-5 minutes.
Put parsnips, carrots, potatoes and the pan mixture into a slow cooker. Cover with broth until everything is submerged and give it a good stir. Place bay leaves on the surface, cover, and let cook on high for 3-4 hours (until veggies are fork-tender).
Around the 3 hour mark, check on your stew, and if it seems close to done, then you can remove the bay leaves and add the frozen peas.
Make a cornstarch slurry by combining 1-2 tbsp of cornstarch with 2-3 tbsp of water and stirring well. Add this to the slow cooker and let it cook for another 20-30 minutes.
Serve warm with crusty bread or your other favourite accompaniments!