Heat a heavy skillet or saute pan over medium heat. Add 1 tbs of the oil. Add the mushrooms; cover and cook for 5 minutes. Remove cover and continue cooking until mushrooms begin to brown. Remove from pan and place in the slow cooker.
Return the pan to the heat. Season the steaks with salt & pepper. Add 1 tbs of oil and brown the blade steaks nicely. Remove to a plate and set aside
Return the pan to the heat and add 2 tbs of the oil. Add the sliced onions, the thyme and the paprika. Stir and cook for about 1 minute. Add the flour and stir well, cooking for about 1 minute. Whisk in the sherry and chicken stock, scraping up all the browned bits at the bottom of the pan. Add the entire contents of the pan to the slow cooker.
Place browned steaks on top of the mushroom/onion mixture. Cover and cook on LOW for 6-8 hours, HI for 4-5 hours.
Remove steaks to a serving plate and cover with aluminum foil to keep them warm. Stir the cream and parsley into the liquid. Heat for another 10 minutes. Ladle gravy over steaks and serve
Makes either 6 smaller servings or 3 larger servings.