Cast Iron Roast Chicken

1, 3-4 Pound Whole Chicken 4 Medium Russet Potatoes, Scrubbed and Thinly Sliced 2 Shallots Thinly Sliced Kosher Salt Black Pepper Olive Oil 1 Lemon, Cut in Half 4-5 Cloves Garlic, Smashed 10- 12 Sprigs Fresh Thyme   Preheat oven to 425 Fahrenheit. Rinse and completely dry chicken. Generously season with approximately 1 ½ tablespoons…