10large (3.5 lb to 4 lb)chicken drumsticks(bone-in skin-on)
To a food processor add parsley, green onions, oregano, garlic and red pepper flakes. Pulse in short bursts about 10 times or so until roughly chopped.
Pour in olive oil, red wine vinegar, lemon juice and process until herbs are somewhat finely minced and liquids come together, about 5 to 10 seconds (stop and scrape down processor if needed).
Scoop out 1/4 cup of the herb mixture into a bowl and season that with a few pinches of salt. Cover and refrigerate.
Season remaining mixture with 1 1/2 tsp salt and 1/2 tsp pepper (you should have about 3/4 cup remaining herb mixture).
Place chicken legs in a gallon size resealable bag. Pour 3/4 cup herb mixture over chicken legs. Seal bag while pressing out excess air then rub marinade over chicken legs to evenly cover.
Transfer to fridge and let marinate 1 hour and up to 24 hours.
Move oven rack up one level from center. Preheat oven to 400 degrees. Spray a rimmed 18 by 13-inch baking sheet with non-stick cooking spray (preferably use a dark coated baking sheet).
Roast legs in preheated oven for 25 minutes. Remove from oven and turn legs to opposite side.
Return to oven and continue to roast until cooked through (center is 165 in thickest portion) about 20 to 25 minutes longer.
Tip during baking: If you find the legs haven't quite browned enough then broil during the last few minutes. If they are over-browning you can loosely tent with foil near the end.
For crispy skin serve as is, or for more flavor brush with the remaining unused 1/4 cup chimichurri herb mixture (not what the chicken marinated in!). If you don't end up using that remaining 1/4 cup then toss it with a vegetable side such as roasted red potatoes or corn.
Nutrition estimate based on half of the oil and salt being consumed, and using 3.75 lb chicken legs.