Rosemary Mustard Sirloin Steaks
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Rosemary Mustard Sirloin Steaks

Rosemary Mustard Sirloin Steaks

with Garlic Mashed Potatoes and Roasted Brussels Sprouts

Demi-glaze is an intensely rich, glossy sauce reduction. A master sauce of French cuisine, traditional demi-glace requires simmering beef stock for hours. But don’t panic---we’ve made it for you! When our own rich, glossy demi is used in the pan sauce for this luxurious dish, it creates a savory depth of flavor that’ll make anyone you feed believe you slaved at the stove for hours. Don’t worry, though--we’ll never tell.


Produced in a facility that processes eggs, milk, fish, peanuts, sesame, shellfish, soy, tree nuts, and wheat.

Total Time40 minutes
Prep Time


/ serving 4 people

16 ounce

Brussels Sprouts

24 ounce

Yukon Gold Potatoes

4 clove


1 unit


4 tablespoon

Sour Cream

(Contains Milk)

28 ounce

Sirloin Steak

¼ ounce


2 unit

Beef Demi-Glace

(Contains Milk)

4 teaspoon

Dijon Mustard

1 teaspoon

Chili Flakes

Not included in your delivery

2 teaspoon

Vegetable Oil

2 teaspoon

Olive Oil

4 tablespoon


(Contains Milk)




Nutrition Values

/ per serving
Energy (kJ)3473 kJ
Calories830 kcal
Fat66 g
Saturated Fat24 g
Carbohydrate55 g
Sugar9 g
Dietary Fiber12 g
Protein48 g
Cholesterol200 mg
Sodium910 mg
Due to the different suppliers we purchase our products from, nutritional facts per meal can vary from the website to what is received in the delivered box, depending on your region.


Large Pot
Baking Sheet
Large Bowl
Large Pan
Paper Towel


Prep and Cook Potatoes

Adjust rack to top position, then preheat oven to 425 degrees. Wash and dry all produce. Trim, then halve Brussels sprouts. Mince or grate 2 cloves garlic (save the rest for later). Zest, then halve lemon. Dice potatoes into ½-inch pieces (no need to peel). Place in a large pot with salted water to cover. Boil until tender, about 15 minutes.

Make Mashed Potatoes

Drain potatoes. Melt 2 TBSP butter in same pot over low heat. Add minced garlic; cook until fragrant, about 30 seconds. Return potatoes to pot; mash with a potato masher until smooth. Stir in sour cream; season with salt and pepper. Keep covered until ready to serve.

Roast Brussels Sprouts

Meanwhile, toss Brussels sprouts in a large bowl with a large drizzle of olive oil and a pinch of salt and pepper. Place Brussels sprouts and 1 lemon half on a baking sheet. (Use the rest of the lemon as you like.) Roast on top rack until golden brown, 20-25 minutes.

Cook Steaks

Pat steak dry with a paper towel; season generously with salt and pepper. Heat a large drizzle of oil in a large pan over medium-high heat. Add steak and cook to desired doneness, 3-6 minutes per side. Turn off heat; remove steak from pan and let rest. Wipe out pan.

Make Sauce

Melt 2 TBSP butter in same pan over medium heat. Add remaining garlic cloves and 1 sprig rosemary (we sent more) and cook, stirring often, until fragrant, about 1 minute. Reduce heat to low. Add demi-glace, mustard, and ¼ cup water. Cook, stirring, until thoroughly combined, 1-2 minutes. Stir in any resting juices from steak. Turn off heat. Season with salt and pepper (to taste). Remove and discard garlic and rosemary.

Finish and Serve

Slice rested steak against the grain. Squeeze as much juice from roasted lemon as you like over Brussels sprouts. Sprinkle with lemon zest and chili flakes (to taste). Divide steak, Brussels sprouts and mashed potatoes between plates. Spoon sauce over steak and serve.