Pound chicken thigh and dust both sides of thigh with flour.
Add half the olive oil to pan and turn to medium/high heat. Once the oil is hot add chicken thighs. Cook for 3 minutes. Then flip and cook an additional 3 minutes. Remove thighs from pan and set aside.
Put the remaining oil into pan. When oil is hot add garlic and onions (scrape up any brown bits of flour). Cook for 2 minutes. Add mushrooms and peas. Cover and cook for 4 minutes.
Return the thighs to the pan and pour in broth, lemon juice, and rind. Stir gently. Cook uncovered for 3 minutes. Stir in tarragon, salt and pepper. Cover and cook for 5-8 minutes until chicken is cooked throughout.