Preheat oven to 425 degrees F. Lightly oil a baking sheet or coat with nonstick spray.
Place potatoes in a single layer onto the prepared baking sheet. Add olive oil; season with salt and pepper, to taste. Gently toss to combine.
Place into oven and bake for 30-35 minutes, or until golden brown, stirring halfway. Set aside and keep warm.
Season chicken thighs with 3/4 teaspoon salt and 1/2 teaspoon pepper.
Melt butter in a Dutch oven over medium heat. Working in batches, add chicken, skin-side down, and sear both sides until golden brown, about 2-3 minutes per side; set aside. Drain excess fat, reserving 2 tablespoons in the Dutch oven.
Add shallot, and cook, stirring occasionally, until tender, about 3-5 minutes. Stir in garlic and oregano until fragrant, about 1 minute.
Whisk in flour until lightly browned, about 1 minute.
Stir in chicken stock and wine, scraping any browned bits from the bottom of the Dutch oven. Return chicken to the skillet.
Place into oven and bake until chicken has completely cooked through, reaching an internal temperature of 175 degrees F, about 12-15 minutes.
Stir in peas and lemon juice until heated through, about 1 minute; season with salt and pepper, to taste.
Serve immediately with potatoes, garnished with parsley, if desired.
Notes
*Chicken stock can be used for white wine as a non-alcoholic substitute.