My favourite beef pot roast with really good gravy

1. Pat roast dry. In large shallow dish, combine garlic and steak spice; rub all over roast. In large dutch oven, heat 2 tbsp oil over med-high heat; brown roast all over, turning with wooden spoons; about 10 mins. Transfer to plate; set aside. Reduce heat to med; heat remaining oil. Fry onions, stirring occasionally until golden, about 4 mins. Put onions in slow cooker and top with roast. Put beef stock in dutch oven bring to a boil; scrape up brown bits and pour over roast. Cover and cook on low for about 7 hrs. Remove roast and cover with foil to keep warm. Whisk flour and 1/2 cup water and whisk into slow cooker. Cover and cook on high until thickened, about 15 mins. Sprinkle with parsley.