To Start
Season the mallards with salt and pepper and heat the oil in a roasting tin or large frying pan over a medium high heat. Brown the mallards on all sides then place the spices and herbs inside the cavity of each mallard along with some of the onions and butter. Place the rest in the roasting tin.
Then
Remove the skin of the oranges with a sharp knife and juice the oranges. Pour the juice of one orange over the mallards and add the orange zest to the roasting tin.
Simply
Heat the oven to 180C/160fan/gas 4 and roast the mallards for 15 minutes. Add the plums to the tin, cover with foil and return to the oven for another 20 minutes until the meat is just cooked and the breast pink.
Now
Remove from the oven and place the mallard, plums and onions on a warm plate to rest while you prepare the sauce. Place the tin over a medium heat, skim off any fat and add the remaining orange juice. Deglaze the tin by scraping all of the residue and bring to a boil then simmer until reduced.
To serve
Carve the mallard, plate and serve with the roasted onions, plums and sauce.