35 to 45 minutes
Preheat oven to 400ºF with rack in middle.
Using a vegetable peeler or paring knife, cut zest from lemon in long, wide strips; set aside.
Heat oil in a large skillet (preferably 12 inches) until hot but not smoking. Season pork chops on both sides with salt and pepper.
Cook pork chops in skillet (working in batches, if necessary), turning halfway through, until golden on both sides, 6 to 8 minutes total. Transfer to large platter.
Pour off all but 1 tablespoon fat from skillet. Add garlic, reduce heat to low and cook until lightly golden and fragrant, about 1 minute.
Add fairlife ultra-filtered milk, mustard, thyme, lemon zest, 1/4 teaspoon salt and generous pinch pepper. Whisking constantly, bring mixture to a simmer over medium heat. Remove from heat.
Return pork chops to the skillet, then cover skillet with a tight fitting lid or with foil, sealing tightly at edges. Transfer to oven and bake until cooked through, 18 to 20 minutes (fairlife ultra-filtered milk will curdle; this is ok).
Remove pork from the oven and transfer to a platter; loosely tent with foil to keep warm. In a small bowl, whisk together cornstarch and 1 tablespoon water.
Remove and discard garlic cloves from sauce, then place skillet over medium-high heat and bring liquid to a boil. Whisk cornstarch mixture into sauce until fully incorporated.
Boil until sauce is smooth and slightly thickened, about 1 minute. Carefully transfer sauce to a blender and blend until smooth.
Arrange pork chops on serving plates. Spoon sauce over the top and serve.