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Sirloin Tip Roast (with mashed potatoes)

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Oven Sirloin with roasted garlic Mashed Potatoes is a perfect dinner dish for you and your family any night of the week. Get a perfectly roasted juicy sirloin steak every time.

sliced roasted beef sirloin with mashed potatoes
sirloin and mashed potatoes

If you’re wondering how to make a beef sirloin tip roast in the oven, look no further. This deliciously juicy roast is made perfectly in the oven and the best part is, you don’t have to constantly check on it.

Simply season your steak, add it to the roasting pan and dinner practically makes itself. Serve this comforting dinner over the garlic roasted mashed potatoes for a complete meal.

ingredients

ingredients for a sirloin roast and mashed potatoes, including garlic dijon, seasoning blend
ingredients for sirloin roast and mashed red potatoes
  • Beef sirloin tip roast is covered in a flavorful rub consisting of garlic powder, dried oregano, minced onion, dijon mustard and olive oil.
  • Red potatoes are made with whole milk, heavy cream, salted butter and grated parmesan for the most flavorful, creamy and fluffy mashed potatoes.

how to oven roast sirloin

Follow these easy steps to make an oven-roasted sirloin.

sirloin roast instructions, including seasoning and adding roasted garlic
instructions for roasting sirloin

Before you begin, rest the steak at room temperature for 30-45 minutes.

  1. Pre-heat the oven to 250 degrees F. Season the roast with your dry rub ingredients. Roast for an hour with the garlic separate.
  2. Brush with dijon mustard.
  3. Add mashed, roasted garlic.
  4. Sprinkle with parmesan and return to the oven for another 45 minutes.

Roasted garlic mashed potatoes

You can make these flavorful mashed potatoes right on your stovetop.

instructions for mashed potatoes
how to make creamy garlic mashed potatoes
  1. Quarter your potatoes and boil until soft.
  2. In a separate saucepan, combine butter and seasonings.
  3. Mash your potatoes and add in the buttery sauce.
  4. Stir.

tips

  • Do not open the oven during the last step of roasting. Slow roasting the steak provides an incredibly tender and juicy steak. Use a meat thermometer as cooking times may vary depending on the size and weight of the steak and ambient oven temperature.
  • Peeling the garlic cloves before adding to the foil will roast them much faster. Because of this, pay close attention to prevent burning.
  • Cutting the potatoes into quarters shortens the cooking time. Test the potatoes are tender and cooked by piercing with a fork. It should very easily pierce through the potato. 
large sirloin in a roasting pan next to mashed potatoes

Temperatures for sirloin

Here are key temperature points you should keep in mind when cooking this meat cut:

  • Internal temperature should be 145 degrees F for Medium, i.e., brown outsides and light pink in the middle. This the point at which beef is considered safe to consume.
  • Internal temperature should be 155 degrees F for Medium-Well, i.e., brown outsides and slightly pink in the middle.
  • Internal temperature should be 165 degrees F for Well-done, i.e., brown outsides and in the middle.
sliced sirloin roast
juicy and tender inside

FAQs

How long to cook sirloin tip roast per pound?

To ensure the sirloin tip roast is cooked to perfection and is juicy and tender without drying out, cook for 20 minutes per pound at 325 degrees F, or if you prefer slow-roasting, cook for an hour per pound at 250 degrees F (medium well).

What is the difference between the New York strip and sirloin?

Here are a few noticeable differences between New York strip and sirloin:

  • New York strip comes from the beef’s prime rib cut, whereas the sirloin is a round cut.
  • Although sirloin is lean meat, the New York strip is leaner.
  • Lastly, the New York strip is an expensive meat cut compared to sirloin, which is more economical and pocket friendly.
sirloin roast on a platter next to garlic

What is the difference between sirloin and top sirloin?

Despite the two meat cuts being boneless, there are a few differences between sirloin and top sirloin. These are:

  • Firstly, the sirloin tip is a meat cut from the beef’s round. Whereas the top sirloin comes from the beef’s sirloin.
  • The sirloin tip is leaner than the top sirloin, but it is tougher than the top sirloin. 
  • Sirloin tip has a more prominent marbling than top sirloin. 
sliced sirloin steak on a platter next to parsley garnish
tender, juicy sirloin roast

leftovers

Place the leftover steak and mashed potatoes separately in an air-tight container and refrigerate it for about 3 to 5 days. You can also freeze leftover steak by wrapping it with heavy-duty aluminum foil and placing it in a ziplock bag before freezing. It will last for up to a month

Best sides with sirloin tip

Sirloin tip goes well with several sides, including

sliced medium rare sirloin roast

Sirloin Roast with Mashed Potatoes

Perfectly juicy, tender Sirloin Roast with creamy garlic Mashed Potatoes.
5 from 1 vote
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Course: Main Course
Cuisine: American
Prep Time: 20 minutes
Cook Time: 2 hours 30 minutes
Total Time: 2 hours 50 minutes
Servings: 9
Calories: 405kcal
Author: Amber

Equipment

  • roasting pan

Ingredients

  • 3 lb beef sirloin roast
  • 1 tsp salt
  • 1 tsp garlic powder
  • 1 tsp ground pepper
  • 1 tsp dried oregano
  • 1 tsp dried, minced onion
  • 2 lbs red potatoes quartered
  • ¼ cup whole milk
  • ¼ cup heavy cream
  • cup salted butter
  • 1 cup grated parmesan
  • 1 bulb garlic
  • 1 tbsp olive oil
  • 1 tbsp dijon mustard

Instructions

  • Before you begin, rest and bring the sirloin roast to room temperature (about 45 minutes).
  • Peel the garlic cloves and place into the center of a square of foil. Drizzle with olive oil and season with a pinch of salt. Close foil and place into the oven as it preheats to 250°F.
  • Season steak with salt, garlic salt, pepper, oregano, and minced onion.
  • Place roast into a pan and into the oven on the center rack. Cook for 1 hour. 
  • Remove the garlic and steak. Brush the steak with Dijon mustard and ½ of the roasted garlic. Sprinkle parmesan cheese generously over the top. Place the steak back into the oven for 55 minutes. 
  • Turn off the oven and let the roast rest inside the oven as it finishes cooking and comes to temperature.
  • Remove the steak from the oven and place onto a wooden cutting board. Let rest 10 minutes. Slice steak and serve with mashed potatoes

mashed potatoes

  • Add quartered potatoes (skin on) to a large pot and fill with water until the potatoes are just covered. Bring to a boil and boil for 15 minutes. 
  • Add milk, heavy cream, butter, and reserved roasted garlic to a saucepan over medium heat.
  • Remove the potatoes from the water and into a large bowl. Lightly mash.
  • Once the saucepan starts simmering, pour it into the bowl with the potatoes and stir until combined Season lightly with salt and pepper to taste. 

Notes

  • Do not open the oven during roasting. Slow roasting the steak provides an incredibly tender and juicy steak. Use a meat thermometer as cooking times may vary depending on the size and weight of the steak and ambient oven temperature. 
Temperatures
  • Internal temperature should be 145 degrees F for Medium, i.e., brown outsides and light pink in the middle. 
  • Internal temperature should be 155 degrees F for Medium-Well, i.e., brown outsides and slightly pink in the middle.
  • Internal temperature should be 165 degrees F for Well-done, i.e., brown outsides and in the middle.

Nutrition

Calories: 405kcal | Carbohydrates: 18g | Protein: 38g | Fat: 19g | Saturated Fat: 10g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 6g | Trans Fat: 1g | Cholesterol: 119mg | Sodium: 636mg | Potassium: 1017mg | Fiber: 2g | Sugar: 2g | Vitamin A: 424IU | Vitamin C: 9mg | Calcium: 156mg | Iron: 4mg

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