I looked at a bunch of recipes with herbs and other seasonings, but in the end, I just used olive oil, salt, and pepper on the roast, and it was perfect.
Preheat oven to 375F, cut up red onion, carrots, gold potatoes, toss with seasonings and oil, pat dry Cornish hens and season the same way, roast for about 1 hr 15 minutes. If they’re not browned enough by that point, bump the temperature to 425F for five minutes or so at the end. So good, so easy. Dinner for four.