I adore peas, probably because they’re one of the few foods that one can feel totally non-guilty about eating frozen. (I’m sure I could google a study showing that, in fact, frozen peas are bad for you and/or the work of the devil but I prefer to remain in ignorance, thanks very much.)
When my sister-in-law cooks a roast lunch, this is how she makes them:
Finely chop an onion and stick of celery, and sauté slowly in a glug of olive oil until soft. Now add some diced pancetta (since they’re frozen peas, I’m sure you’re allowed to use those handy packets of lardons) and fry that too until cooked. Then add in your peas straight from the freezer with a very small amount of water, just so they have a little steam to breathe in. You can cook these as gently or fiercely as the timing for the rest of the roast dictates (and you can reheat in the microwave), so it’s a zero-stress vegetable.