An easy-to-make sheet pan meal made with the simplest of ingredients: chicken thighs, leeks, potatoes, garlic, lemon, and seasonings.
Preheat the oven to 425F.
Place the sliced leeks in a medium bowl filled with water. Let the leeks soak for about 5 minutes. Drain the water from the leeks using a colander. Rinse the leeks under water to remove any remaining dirt particles. Dry the leeks.
Arrange the leeks, potatoes, and garlic cloves on the sheet pan. Pour half the olive oil over the veggies (you don't need to be precise with your halving, just as close as possible), and squeeze half of the lemon over the veggies. Sprinkle with 1 tsp of salt and 1/4 tsp of the black pepper. Toss to combine. Push the veggies to the edges of the sheet pan, forming a space in the center of the sheet pan for the chicken.
Arrange the chicken in the center of the sheet pan. Drizzle the remaining olive oil over the skin of the chicken thighs, and squeeze the juice from half the lemon over the chicken. Sprinkle the skin with the remaining salt, pepper, and all the thyme. Rub your hands over the skin to evenly distribute the spices, if needed.
Place the sheet pan in the center rack of the oven, and bake for 35-45 minutes, or until the veggies are cooked through and slightly crisp on some edges and the chicken is cooked through (the juices run clear) and the skin is brown and crispy. The veggies should be more steamed than crispy. Check on your chicken around the 35 minute mark to determine how much longer you'll need to cook your chicken--the skin should begin to brown and look crisp right about now. 45 minutes works best for my oven and crispy skin preference so that's my recommendation, but cooking times can slightly vary with each oven. The good thing about thighs (with the skin and bones) is the meat will stay moist even with a few extra minutes of cook time.
For the veggies, you can pierce the potatoes with a fork to check for doneness. If your potatoes were cut into larger chunks, you may need to remove the chicken from the sheet pan and then return the potatoes and leeks to the oven to finish cooking. I've never had to do this (I also go with a full 45 minutes), but it's worth noting depending on the size of your potato chunks and how quickly your chicken cooks (say 30-35 minutes instead of the full 45 minutes).
Remove the sheet pan from the oven and serve warm. Taste the potatoes and add more salt or pepper, until seasoned as desired.
When storing any leftovers, be sure to add the juice from the sheet pan to the chicken and veggies. This juice is full of flavor and will also keep the chicken and veggies tender and moist when reheated. I also love to spoon the juice over the veggies when serving the meal. It makes a delicious jus-like sauce (or gravy).
*Do not use boneless, skinless chicken thighs, or chicken breasts. This recipe works because of the dark, juicy chicken thighs and using thighs with bones is a must.
The amount of olive oil used creates the loveliest gravy-like sauce for the potatoes and leeks to cook in, and it's particularly flavorful when combined with the chicken. If you don't want to use as much oil, and don't want such "saucy" veggies, you could reduce the amount of olive oil by 1-2 tablespoons, if desired. This will produce drier veggies, so you may want to grease the sheet pan first before adding the veggies to the pan.