Scrub and rinse potatoes. Put a colander in the sink. Bring a medium pot with potatoes, water that rise 1" above potatoes and a pinch of slat to a boil over hight heat. Once pot reaches a boil, reduce heat to a slow boil. Cook until tender, about 20-22 minutes. Potatoes should be easily pierced with a knife.

While potatoes are cooking, heat a medium pan over medium heat. Rinse chicken and pat dry. Season thighs with salt and pepper and place in hot pan with 1 Tbsp. olive oil. Sauté until golden brown, about 6-8 minutes on each side or until internal temperature reaches 165 degrees. Remove the cooked chicken from the pan and set aside.

While chicken is cooking, thoroughly rinse produce and pat dry. Mince chervil. Zest lemon, mince zest and juice half and reserve. Mince garlic. Thinly slice green onion tops on the bias (45 degree angle). Finely chop green onion bottoms (white parts). Mix chervil, garlic and lemon zest in a clean mixing bowl. Season with a pinch of salt. This mixture is the gremolata.

Warm the same pan you used to cook the chicken over medium heat. Add 1 tsp. olive oil and the finely chopped green onion bottoms to the pan. Sauté for 1 minute, then add cooking wine and mustard. Cook until slightly reduced, about 2 minutes. Add in reserved lemon juice to taste. Remove pan from heat and whisk in butter until incorporated. Butter will thicken and enrich the sauce as it emulsifies with the wine and mustard.

When the potatoes are tender, strain and carefully slice in half. Place in a bowl with sliced green onions. Drizzle with 1 Tbsp. olive oil and season with a pinch of salt and pepper. Use spoon, fork, or potato masher to smash ingredients together.

Place a serving of potatoes on a plate and sprinkle with a half the gremolata. Place two chicken thighs on top of the potatoes. Drizzle the pan sauce over the chicken, potatoes, and plate. Garnish with remaining gremolata.