Let's marinate the chicken to start. I like to brine my chicken the day before, but it's not fully necessary, so up to you! If you're not brining, next, heat up a pan, or a grill.
On a sheet tray, shallow dish or pan, add in your chicken legs and marinate your chicken by seasoning with olive oil, melted butter, a pinch of paprika, salt, pepper, lemon juice, lemon zest and thyme. Set aside to marinate or cook immediately. Place on your heated grill to grill chicken, or in a large skillet on the stove top.
While your chicken is cooking, make your sauce. On the grill, oven or stovetop, char your leeks (wash and trim) and cut in half vertically, green onions/scallions, jalapeño as well as lemon halves. Season with salt, pepper and a drizzle of olive oil. Add on the grill or stovetop until charred.
Keep an eye on your vegetables, the lemon will be taken off first, then the green onions and the leeks last - according to your preference of char. Remove all and let cool until cool enough to handle.
When cooled, finely slice your leeks, green onions and jalapeño. Place your mixture in a small bowl to medium sized bowl and drizzle with olive oil, salt, pepper, sugar, minced shallots and dijon mustard, as well as your charred lemon juice. Mix.
When your chicken is crispy on the outside, and cooked on the inside, remove from the grill or stove, serve with your charred leek sauce either on top of the chicken, underneath the chicken, or served alongside. It should be tangy and super saucy! Enjoy!