Easy Herb-Rub Pork Sirloin Roast

A simple fresh herb rub and plenty of garlic make this Easy Pork Sirloin Roast a reliably delicious, budget-friendly main. It’s an ideal way to prepare Costco’s boneless pork sirloin roast: quick to assemble, forgiving to cook, and tender and flavorful every time. Serve it for a weeknight family dinner or a small gathering—leftovers reheat beautifully.

Why this recipe works

Boneless pork sirloin roasts are affordable, usually around 1½ to 2 pounds each, and they roast evenly. The technique here is straightforward: slivered garlic is tucked into small pockets cut into the meat, and a bright herb-and-mustard rub is massaged over the surface. A brief rest in the refrigerator allows the flavors to penetrate, and a short oven roast brings the pork to a safe, juicy finish. Letting the roast rest after cooking ensures the juices redistribute, keeping each slice moist.

Ingredients

• 1½ to 2 lb boneless pork sirloin roast
• 3 to 4 large garlic cloves, peeled and cut into slivers (about 3–4 slivers per clove)
• 2 tablespoons finely chopped fresh rosemary
• 1 tablespoon fresh thyme leaves
• 2 teaspoons ground dry mustard
• 2 tablespoons olive oil (or a neutral oil of your choice)
• 1 teaspoon Kosher salt (adjust if using table salt)
• ½ teaspoon freshly ground black pepper
• Optional: 1 lb potatoes or other root vegetables, cut and tossed with olive oil, salt, and pepper to cook beneath the roast

Preparation and cooking tips

1. Pat the pork dry with paper towels. Drying the surface helps the rub adhere and lets the meat brown more effectively.

2. Use the tip of a sharp knife to make small pockets all around the roast at varying depths. Slide a garlic sliver into each pocket; for stronger garlic flavor, make some pockets deeper so the garlic infuses the interior of the roast.

3. In a small bowl, stir together the chopped rosemary, thyme, dry mustard, olive oil, Kosher salt, and freshly ground pepper. Rub the mixture evenly over the entire roast. Place the seasoned roast in the refrigerator for at least one hour; several hours or overnight will deepen the flavor.

4. When ready to roast, preheat the oven to 350°F (175°C). If you want a one-pan meal, spread prepared potatoes or root vegetables in the bottom of a deep roasting pan and drizzle them with oil, salt, and pepper. Place a rack over the vegetables and set the roast on the rack so drippings flavor the vegetables as it cooks.

Cooking instructions

1. Preheat oven to 350°F (175°C).
2. Place the roast on a rack in a deep roasting pan above any prepared vegetables or in an empty pan if you prefer.
3. Roast for 60 to 90 minutes, until an instant-read thermometer inserted into the thickest part reads 145°F (63°C).
4. Remove the roast from the oven and let it rest for 10–15 minutes before slicing. Tent loosely with foil if you want to keep it warm while it rests.

Serving suggestions

Slice the roast thinly and serve with the roasted potatoes or root vegetables cooked beneath it. A simple green salad and crusty bread make nice accompaniments, or serve with steamed green beans or sautéed greens for a lighter plate. The herb-and-garlic juices from the roast also make a flavorful base for a quick pan sauce—deglaze the roasting pan with a splash of stock or wine and simmer briefly, scraping up browned bits.

Notes

• If using table salt instead of Kosher salt, reduce the amount by about half.
• Freshly ground pepper and fresh herbs make a noticeable difference; use them when possible.
• This recipe scales easily—double the ingredients for two roasts and adjust cooking time if you roast multiple pieces together.

This easy herb-rub pork sirloin roast is an excellent, budget-conscious choice that delivers tender slices and plenty of flavor. It’s quick to prep, forgiving in the oven, and perfect for both casual family dinners and entertaining guests.