Preheat the oven to 425°F. Spray a sheet pan with nonstick cooking spray or brush liberally with canola oil.
Remove chicken from packaging. Rinse and pat dry with paper towels.
In a small bowl, stir together 2 teaspoons sea salt, 1 tablespoon lemon pepper, lemon zest, lemon juice, and chopped thyme to make a paste.
Drizzle 2-3 tablespoons of canola oil over the chicken pieces and rub to completely coat them. Rub the seasoning paste onto both sides of all of the chicken. Place the prepared chicken on an oven-safe rack set in a large sheet pan.
Cut the potatoes in half lengthwise (or into quarters if the potatoes are larger). Drizzle with 1-2tablespoons of oil and sprinkle with an additional teaspoon of salt and lemon pepper. Toss to coat the potatoes.
Spread the potatoes on the sheet pan around the rack with chicken. If necessary, use a second sheet pan for the potatoes and asparagus.
Place pan with chicken and potatoes into the oven and bake for 20 minutes.
Meanwhile, prepare the asparagus by snapping the woody base of the stem from each asparagus spear. Rinse and air dry the asparagus. Drizzle with a bit of oil and season with any of the seasonings you used on the potatoes and chicken (salt, pepper, lemon zest, and/or lemon pepper are all good choices).
After the chicken and potatoes have cooked for 20 minutes, add the prepared asparagus to the panto cook for an additional 10-15 minutes.
After 30 minutes of total bake time, check the chicken for doneness - the skin should be crispy and beginning to brown and the internal temperature should reach 165°F. Continue cooking until the chicken is done.
When chicken is cooked (check the internal temperature to ensure it has reached 165°F, remove sheet pan from oven.
Serve immediately with lemon slices if desired.