Preheat the oven to 350 degrees F.
Use a long, narrow boning or paring knife to cut several deep slits into the roast. Push the garlic slices into those slits. Place the roast in a small roasting pan and season with salt and pepper. Roast for 45 to 50 minutes, or until the centre of the meat registers 160 degrees F on a meat thermometer. Set the roast on a plate, tent with foil and rest 10 minutes.
Meanwhile, set the roasting pan on the stovetop over medium-high heat. Pour in the lemon juice and simmer until reduced by half. Add chicken stock/flour mixture. Simmer until a lightly thickened sauce forms, and then stir in the herbs, salt and pepper.
Slice the pork and serve the sauce alongside.