Combine flour, salt, pepper, onion powder, and thyme in a big ziplock bag. Shake, then add the stew meat. Shake to coat the pieces evenly. Brown the meat in the cooking oil on all sides, you don't need to cook the meat through. You may need to cook the meat in batches. Dump the meat into the slow cooker. Put the pan back on the stove and de-glaze the pan with the beef broth, and tomato paste, scrape up any brown bits of meat and flour into the sauce. This will only take a minute or so. Add the sauce to the slow cooker. Add the potatoes, carrots and onions to the slow cooker. Give everything a big stir. Cook on low for 7 to 8 hours. Add peas at the end of cooking time. Put lid back on and cook for 15 more minutes or so, to thaw the peas.