Preheat the oven to 200 °C.
Lightly coat the shanks with the flour and brown in a heavy-based saucepan in the heated oil.
Remove the meat.
Arrange the lemon quarters and half the peppers, oregano, garlic and chillies in the bottom of a casserole dish.
Place the shanks on top and the rest of the peppers, oregano and chillies on top.
Add the wine and stock.
Cover and place in the oven for 40 minutes, basting the shanks with the liquid from time to time.
Reduce oven temperature to 160 °C and cook for another two hours.
If the gravy is too runny, remove the lid and simmer for 10 minutes on top of the stove.
Serve with Patatas bravas