Rinse and pat dry hens. Gently loosen skin from flesh of bird with your fingers
Place butter pieces under skin through breast, back and leg area of hen
Brush skin of hens generously with melted butter
In a small bowl combine together spices for rub
Rub exterior of hens with herb rub. Set birds into a shallow baking dish and allow to come to room temperature; or cover with plastic wrap and keep in the refrigerator overnight if planning ahead. When ready to roast, be sure to let the hens come to room
Start making the glaze. Combine all of the ingredients into a small saucepan and reduce liquid over medium high heat for about 20 to 30 minutes or until reduction has a syrupy consistency
This usually happens when liquids have reduced a little more than 3/4th of the way. Check reduction often so it does not evaporate and burn
Once glaze looks syrupy and coats the back of a spoon, turn off heat and strain into a heat proof bowl. NOTE: Glaze will thicken slightly as it cools
Meanwhile place half of the carrots into the middle of a cast iron skillet and place one hen right on top, add half of the pearl onions around the sides. Repeat using another cast iron skillet with the other hen and remaining vegetables
NOTE: if using a roasting pan, you can roast both birds in the same pan. Place each hen, breast side down on top of a cross-hatch of carrots, so that the skin does not stick to the pan during roasting
Roast breast-side down for 15 - 20 minutes or until golden. Remove from oven, brush with glaze and then using tongs, turn hen over. Add lemons and thyme sprigs and roast breast side up for another 15 to 20 minutes
Remove from oven and check temperature. If thermometer reaches 160 F and juices look clear between the leg and thigh area, the hen is done and can be glazed. If not, roast for another 8 to 10 minutes and check temperature again
Once internal temperature of hen reaches 160 F, coat with remaining glaze and cook for another 5 to 10 minutes
When hen is finished roasting, take out of the oven and allow to rest for 15 minutes before carving and serving
