I hit them with olive oil and salt, no pepper. I know some people that don't use anything, and some who use butter.
For the sake of science dank, I must inquire as to your method.
Love me some garlic. When I cook a traditional Chicken with 40 Cloves of Garlic, it always comes out more like Chicken with 74 Cloves of Garlic.
EVOO and salt for the garlic. The veggies get the same but also pepper and thyme and rosemary. Sometimes cayenne if I know my wife won't be eating any of the batch, but that is rare. Roast the veggies until mostly soft and then a quick burst under the broiler for some extra color and flavor. Need to let the final product meld for 24 hours for best results.
You can use any veggies you want but I typically use onion, carrot, celery, red orange and yellow peppers, and lately even some broccoli. I hate broccoli, but this is a good way to get some in me without ruining the flavor.
Freeze the block of cream cheese during the last 10-15 minutes of roasting so it doesn't stick to the foil. Mix the garlic and cream cheese first until well combined. Then add the veggies and refrigerate. I add a lot of veggies, it's more about them than the cream cheese.