I am a fan of the cornish hen. We don’t get poussin where I live so cornish hen is my go to stand-in. One bird is enough for two moderate portions so even a dinner for eight isn’t that hard to do. Dijon mustard and cream work well together. There’s a trick to make them come together though. Add a bit of stock or water to the mustard to thin it. Stir it up before you add it to the sauce. That way you won’t get clumps of mustard floating around in your sauce. Unless you like clumps of mustard, I guess.