I think your nuts is what I think. You wouldn't be at all happy with the results of a 450F oven sear followed by braise at 325F. Think Kevlar.
Fortunately, no wheel requires invention. It's a traditional dish all around the Med; and is called gigot a la culliere
(means spoon lamb) or gigot de sept heures
(cooked for seven hours) in French. It's one of the things every good cook should learn -- and no one's born knowing it.
The recipe I'll give you is for a larger, bone-in leg. Not to worry, I'll give you some notes -- since you've already started in your own way.
GIGOT DE SEPT HEURES
4 to 8 carrots, depending on size
1 leg of lamb, bone in, about 5 - 6 pounds.
4 tbs extra virgin olive oil, divided
1-1/4 cup white wine
1-1/4 cup beef, chicken or mixed stock
8 cloves of garlic
1 or 2 bay leaves
bouquet garni (handful of parsley leaves and stems, couple of thyme stems)
2 tbs (Greek) brandyTechnique
Slice the onion, not too thin. Depending on carrot size, leave then whole, cut in half or quarters. Peel the garlic cloves, but leave them whole.
Preheat the oven to 225F (NOT 325!!). Preheat a heavy casserole on top of the stove. When the casserole is hot, add 2 tbs olive oil. Brown the lamb on all sides in the hot oil -- about 10 minutes in all. Remove the lamb from the pot, and set aside. Pour off the fat and oil from the casserole.
Add the remaining oil oil and return the pan to the stove. When the oil is hot enough, saute the onions and carrots. When the onions are translucent, push the carrots and onions to one side and add the tomato paste to the bottom of the pan. Allow it to brown briefly, then push the vegetables through the past. Cook a little while longer until the paste begins to darken.
Deglaze the pan with the stock and wine. Add the garlic, the bay leaves, the bouquet garni, and return the roast to the casserole. Bring the stock to the simmer, remove from the heat, cover and place in the oven.
Turn once after two hours, and again after four.
Cook for five hours and check for tenderness. Lamb is done when tender enough to eat with a spoon (five to seven hours).
Remove the lamb from the pot very carefully, it's fragile, place on a warmed serving platter. Strain the stock, arrange the vegetables with the lamb, and discard the bouquet garni
, the garlic and the bay leaves.
Defat the stock as best you can. Return the stock to the heat, add the brandy. Bring it to a fast boil and reduce by about 1/3. Taste and adjust for salt and pepper. Sieve and serve alongside the lamb. Garnish the lamb with sprigs of thyme and rosemary. Serve with a spoon, a la culliere
, as the French say.NOTE: You need to cut all the ingredients by about 1/3 to 1/2, and cut cooking time too. Don't worry too much if your ratios are inexact. It doesn't matter at all with this. I'm not sure about how many cloves of garlic you'll want for the braise -- since you've already got so much in the lamb. But heck, you're Greek. Four more sounds right.
Start by wiping the marinade off your lamb and letting it temper for about 20 minutes before browning. If you don't have a casserole, use your roasting pan and cover it very tightly with foil for its time in the oven. I'm guessing your lamb will be done after about 4 hours but allow five. If it's done too early, hold it in the casserole in the oven with the door closed and the fire off before the straining and defatting. Allow about 15 minutes for the whole strain/reduction thing. The reduction will go quickly in a pan with so much surface area.