Preheat oven to 450°F
Cut potatoes in halves or quartersso they are all roughly the same size (about an inch thick) then cut ¼ of the onion and set aside. Cut the remaining onion into thick slices.
Put potatoes and sliced onion in a bowl. Drizzle over olive oil (approx. 2 tbsp) and add 2 tsp of garlic powder, 2 tsp of onion powder, salt & pepper and toss altogether. Set aside.
Place chicken in a baking dish and rub in some salt inside the chicken. Then stuff the ¼ onion, lemon, garlic, rosemary sprigs & thyme sprigs inside chicken as well.
Melt butter and drizzle over the chicken rubbing it in so it gets evenly distributed. Next drizzle some olive oil and sprinkle remaining onion powder and garlic powder, paprika and salt & pepper over outside of chicken. Optional to use cooking twine to tie the chicken legs together for baking.
Bake chicken for 30 minutes then take out chicken and place the potato and onion mixture around the chicken and put back in oven and bake for about 30 minutes longer (until fully cooked). Note: at the 15 minute mark, toss around the potatoes and onions so they bake more evenly.