Make the Spicy Rhubarb Compote in advance if desired and keep it chilled until needed.
Divide the chicken legs into thighs and drumsticks if desired. Place the chicken in a bowl, season generously with salt and pepper, and scatter thyme sprigs over top. Chill for at least 1 hour if time allows.
Remove the chicken from the fridge before searing. Remove the thyme sprigs, but keep them.
Preheat the oven to 375F with a rack in the middle.
Heat a large cast iron or oven-safe skillet over medium-high heat. Add 1 tbsp butter and 1 tbsp cooking oil.
Sear the chicken in batches, skin-side down, until golden brown, about 4-5 minutes. Check around 3 minutes and adjust heat if needed.
Turn and sear the other side. Transfer chicken to a plate. Wipe the skillet and add more fat if the pan bits start to burn.
Add the spring onions or scallions to the remaining fat and cook until just softened, about 4 minutes.
Add the minced ramps or garlic, thyme leaves from the reserved sprigs, and Rose Harissa. Stir in.
Cook for another minute.
Add the additional chicken stock and bring to a boil, scraping up browned bits from the skillet.
Reduce by about one-third, about 5-7 minutes.
Add the chicken stock and rhubarb compote. Stir to combine.
Add the chopped fresh rhubarb and stir.
Place the chicken pieces on top and bring the liquid to a boil.
Transfer the skillet to the oven.
Bake until the chicken is cooked through, about 25-35 minutes depending on size. About 10 minutes before it is done, baste the chicken with pan liquid to create a glaze. Cover loosely with foil if it browns too much. Chicken should reach 165F.
Transfer the chicken to a platter.
Return the skillet to the stovetop over medium-high heat and stir the sauce until the rhubarb melts evenly. Taste and season with salt and pepper. Add 1-2 tbsp honey if needed, starting with less.
Garnish the chicken with fresh ramp leaves and rhubarb confetti.
Serve the sauce on the side or underneath the chicken pieces.