Here's a similar recipe that my family likes a lot. I modified and expanded on the instructions to make it easier for my daughter, who isn't all that experienced in the kitchen. It may give you a few useful hints and ideas.
ROSEMARY ROAST CHICKEN WITH
ONION-GARLIC GRAVY
1 whole chicken (about 3½ pounds)
1½ tablespoons olive oil
4 medium onions, cut in large chunks (3 really large onions will do)
1 lemon, cut in quarters, seeds removed
2 fresh rosemary sprigs (about 6 inches each)
8 whole garlic cloves, peeled
1½ cups chicken broth (unsalted canned is fine)
Salt and pepper to taste
Preheat the oven to 450 degrees (yes, I mean 450).
Remove and discard the giblets, rinse the chicken, pat dry and remove excess fat from around the tail area.
Rub the chicken inside and out with ½ tablespoon of the olive oil, sprinkle with salt and pepper inside and out.
Stuff the cavity with about ½ to 1 of the chopped onions, 2 wedges of lemon, a sprig of rosemary, and 4 garlic cloves; close cavity with toothpicks to keep veggies inside.
Use a bit of the remaining olive oil to grease the bottom of a glass baking dish. Place the remaining onions and garlic in the dish. Drizzle the remaining oil over the onions.
Place the bird breast down on the onion mixture; squeeze juice of another quarter of the lemon over the chicken.
Roast for about 20 minutes per pound. Check the onion mixture; if it starts to blacken or stick, add a bit of the chicken broth.
After 30 minutes, turn the chicken breast side up and add ¼ to ½ cup chicken broth to the onion mixture.
Return pan to the oven and roast until the meat in the thickest part of the leg just loses its pinkness. Add a bit more of the chicken broth if onions start to dry out.
Remove the chicken to a platter.
Scrape the onion mixture into a medium sauce pan. Season with salt and pepper to taste.
Add the leaves from the remaining rosemary (discard stem) to taste. Squeeze in the juice of the remaining lemon quarter. Puree with a hand blender, adding remaining broth if the gravy is too thick. Bring pureed mixture to a boil to meld flavors.
Cut the chicken in serving pieces and serve with the gravy.
(NOTE: if you don’t have a hand blender, which is also called a wand or immersion blender, put onion mixture and other ingredients in a food processor or regular blender, puree, then transfer to sauce pan.)