I don't use bistro granules, but I do use bistro powder as the basis of my gravy. I add a good glug of wine to the mix, and usually the water I have boiled carrots in or else some stock (if I've had time to make turkey stock - veg stock would work well). I often season with some Worcestershire sauce if serving beef, a dash of balsamic for pork, etc.
You could do most of the gravy using a veg basis, put aside a small pot for the veggies, and then add the meat juices and any specific beef-related seasonings for the meat eaters.
Roasted root veg can suit everyone. Steamed carrots and parsnips (10 minutes only needed) and tossed with onion, garlic, butternut squash, juice of a clementine, olive oil, dash balsamic, thyme, salt, pepper) and into the oven. (Sorry, I know the dreaded squash, it's not entirely necessary but we like it mixed into the veg this way).
Sprouts are easy to either pull out a couple of servings before adding pancetta, or to do a few plain steamed servings if you already have the steamer out.
Maybe 1 extra plain veg like peas which you can have in the freezer and cook last minute if you need something more.
Something like stuffed peppers (rice or couscous based) stuffed mushrooms (bread stuffing, or blue cheese based) , stuffed courgettes (diced veg and couscous or rice again) could all be prepared in advance and go into the oven once the beef is out and resting. As a way to avoid the nut roast/Wellington/squash options. These are all available to buy or easy to make at home.
You could do a small pan of roasties in olive oil alongside the big tray of beef dripping ones. Maybe cut the veggie ones a different way (you could do them as smaller sized, or diced, or roasted baby potatoes still with skin on) to make it easy to identify on the table.