Once the tomatoes go into the oven, place the chicken breasts onto a cutting board and cut a pocket into one side of each of them using a paring knife. Spread about 1 teaspoon of chutney and place 2 slices of cheddar inside the pocket of each. Season the outside of each breast with salt and freshly ground black pepper.
Place a medium-size skillet over medium-high heat with 1 turn of the pan of EVOO, about 1 tablespoon, and sear the chicken breasts in the large pan until golden brown, 3-4 minutes per side.
Once the chicken is seared on both sides, transfer them to the oven to finish cooking, about 5-6 minutes (if your pan is oven-safe, just put the whole pan in the oven. Otherwise put the meat onto a baking sheet before moving it to the oven).
Once the chicken goes into the oven, place another large skillet over medium-high heat with 2 turns of the pan of EVOO, about 2 tablespoons. Add the bacon and cook, about 2-3 minutes. Once the bacon starts to brown, add the leeks and cook until tender, another 4-5 minutes.
When the vegetables have finished roasting, transfer them to the skillet with the bacon and leeks, add the chicken stock, and mash everything up together. Season everything with salt and freshly ground black pepper.
Serve up the cooked chicken breasts with a scoop of BLTPs alongside.