Preheat the oven to 400°F or 205°C. Cover your sheet pan with tin foil. Pat chicken as dry as possible, then rub olive oil and some salt onto chicken and spread a bit of olive oil on the sheet pan.
Once the oven is up to temperature, add the chicken, skin side up, and cook for 25 minutes.
Meanwhile, mix remaining olive oil, salt, lemon, sweet peppers, tomatoes, garlic, shallots, and thyme in a bowl. Remove the chicken from the oven and add the remaining ingredients around the perimeter of the sheet tray.
Cook for another 25 minutes or until the peppers are sweet and slightly charred, the chicken skin is crisp, and its internal temperature reads at least 165°F (74°C).
Remove the thyme leaves from the stem and discard the stem.
Let the garlic cool for a minute or so until ready to handle, or use a knife to extract the garlic from its skin. Chop the garlic and mix into the dish. Squeeze the lemon (being careful not to burn yourself) over the vegetables and serve.