Reduce the heat slightly and add the onions to the pan with a dash more oil, if needed. Fry for 8-10 minutes, or until soft and lightly golden. Sprinkle over the flour and stir until combined, then slowly pour in the ale, a little at a time, stirring continuously until the flour has absorbed the liquid and expanded (this prevents clumps from forming). When all the ale has been incorporated, add the herbs and sugar. Bring to a simmer, then return the steak to the pan along with the stock. Return to a gentle simmer, cover and cook over a low heat for 2 hours-2 hours 30 minutes, or until the meat is very tender. Remove the lid for the final 20-30 minutes to reduce the gravy so it’s thick enough to coat the meat.