Slow roasted silverside

We had a beast done and so have several pieces of silverside. Looking for a change to slow cooking in a liquid I found this recipe and intend to try it. I'd like the opinion of others as to whether or not you think cooking it in an oven bag would make it (possibly) more tender.
Here's the recipe.Ingredients
•2 tbs wholegrain mustard
•3 tbs marmalade
•1/2 lemon juiced
•1 garlic clove crushed
•1/4 tsp pepper ground
•2 tbs olive oil
•1 1/4 kgs silverside corned beef

Method
•STEP 1 Preheat oven to 220C.
•STEP 2 Combine mustard, lemon juice, marmalade, garlic, pepper and olive oil.
•STEP 3 Rinse corned silverside and place on baking tray damp. Do not pat dry.
•STEP 4 Baste with mustard mix and cook at 220C for 10 minutes then reduce the heat to 140C.
•STEP 5 Roast for 3 hours. Baste with mustard mixture approximately every hour.
•STEP 6 When finished cooking remove from oven, cover with foil and allow to rest for 30 minutes before carving.

Thanks in advance ;)

Hmmm, cooking in an oven bag is like cooking in a slow cooker but noticed in the above recipe of the temperatures used.
When using temperatures like this is when one wants a certain finish to the meat, hence the thought of "do not use the oven bag".

Maybe as suggested at the end re foil use, this could be used once temperature is lowered. Even then will alter the cooking process as intended with this recipe.

Just thoughts being floated.

Cheers.

Exactly the kind of ideas I was after.
I really hadn't realised how the cooking in the bag was similar to crockpot until you mentioned it.
Thanks so much

Roated Silverside has always given me heartburn as more of the brining solution is retained. I know of others who always roast but it didn't work for me.

Silverside is not always brined. I would have only roasted ubrined meat, i.e. not corned beef.

I base mine on Alison Holst which uses an oven bag too, I usually just put in a lidded roasting pan. From memory water, dill, celery seeds and garlic are the main flavourings, maybe bayleaf too.

Easy and moist.

O/P i have a few pieces of silverside in the freezer from a beast also, do my pickled pork this way and its delicious thanks to our fisher on here. Am going to try it with a piece of silverside in c/p just havent got round to it yet, so good on these hot days not having oven on lol.

Mix together 2 tbsp honey and 2 tbsp wholegrain mustard with a little salt and black pepper Warm in saucepan on low heat. Wash brine off meat under cold running water.
Pour mix over meat and cover well. Wrap and seal in tinfoil pocket.
Place the wrapped meat on an upturned saucer in the crockpot and pour about an inch of water in the bottom.
Leave on low all day and place still wrapped on bench for half an hour to rest. Slice and serve thought it might work.

Getting hungry as a caterpiller reading this. caterpillar? caterpiller?. hungry as a greedy bug