Mustardy Pork Sirloin Roast

Last Updated on September 17, 2023

Mustard’s tangy, floral spice just hits right with pork and here with ButcherBox’s Pork Loin Roast you can feel like an expert roaster/flavor builder with mostly pantry ingredients. As well as the star (*ButcherBox Pork*), baby potatoes and garlic roast alongside to round this out for a quick, easy weeknight or occasional dinner. 

Mustardy Pork Sirloin Roast

3.77 from 72 votes
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Prep Time: 20 minutes
Cook Time: 55 minutes
Servings: 4


  • 2 - 3 1/3 lbs ButcherBox Boneless Pork Loin Roast (2 loin pieces)
  • 1 tbsp Diamond Crystal kosher salt, plus more for seasoning
  • 1 tbsp finely chopped thyme leaves and tender stems plus 6 whole tender stems 
  • 3 small dried bay leaves, finely crumbled
  • 2 tbsp apple cider vinegar 
  • 2 tbsp olive oil, plus more for drizzling 
  • 2 tbsp whole-grain mustard
  • 1 tbsp dijon mustard 
  • 1 tsp freshly ground fennel seeds
  • 1 tsp freshly ground black pepper
  • 1 tsp crushed chili flakes 
  • 2 tbsp unsalted butter
  • 1 lb 1 pound baby potatoes scrubbed clean and cut in half if ping pong ball sized or larger 
  • 2 whole heads garlic, sliced in half, creating 4 cross-sections
  • Flake salt


  • Place the loin pieces in a 9x13x2-inch baking dish and rub all over with the mustard mix. Heat the butter in a large skillet over high heat. Once melted, sear the loin pieces in batches, until golden, about 1–2 minutes per side. Transfer back to the baking dish. Arrange the potatoes, garlic halves and thyme stems around the seared loin pieces. Drizzle the potatoes and garlic with olive oil and place the dish on the middle rack of the oven. Roast until the loin pieces read 145 °F (62.8 °C) with a thermometer inserted into the center of the thickest end, about 30 minutes. Transfer the loin roasts to a cutting board and tent with foil until ready to serve. 
  • Toss and turn the potatoes and pour ½ cup water into the baking dish; keep roasting until the potatoes are steamy and tender and garlic is golden, about 20–30 minutes longer. 
  • To serve, slice the loin thinly and plate on individual plates or serving platter with the potatoes and garlic arranged around. Pour juices over the loin and potatoes and sprinkle it with flake salt.
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