"Create a 6-serving pork roast recipe that is corn-free, gluten-free, and dairy-free. Use a pork shoulder roast or pork loin roast, and include simple vegetables like potatoes, carrots, onion, and garlic. Keep it beginner-friendly, minimal processing, and use imperial units only. Include a straightforward oven method and an optional gravy or pan sauce thickened without flour, cornstarch, dairy, or corn. Avoid dairy, gluten, corn, nuts, soy, sesame, and shellfish."