Season the steaks on both sides with salt and pepper. Heat 1/8 cup of the canola oil in a large saute pan over medium-high heat. Dredge the steaks in flour, and shake to remove excess. Sear the steaks on both sides, remove from pan, and set aside on a utility platter. Add the other 1/8 cup of canola oil to the same pan and saute the onions and mushrooms until the onions become translucent, about 3 to 5 minutes. Add the chicken or beef broth, porter beer, molasses, thyme, hot sauce and bay leaves to the onion/mushroom mixture. Reduce the heat to low and return the steaks to the pan. Simmer covered for at least 2 hours. Rump steaks are a tough meat and will require slow cooking (braising). You may wish transfer the ingredients to a crock-pot for this process. When the steaks are fork tender, remove them to a platter in a warm place. The liquid in the pan should have evaporated to a large degree, intensifying the flavor. If necessary, increase the heat to reduce and thicken into a sauce. Whisk in the butter and creme fraiche or sour cream to finish the sauce, and spoon sauce over the steaks. Garnish with the fresh chopped chives.