Mustard Chive Flank with Slow-Roasted Tomato Pasta Salad

Flank steak has a deep, meaty flavor, and you’ll love how quickly it cooks. It’ll echo the depth of the slow-roasted tomatoes, and contrast nicely with the sharpness of the champagne vinegar. Don’t be surprised if your friends think you picked this up from that gourmet bistro down the street.

Mustard Chive Flank with Slow-Roasted Tomato Pasta Salad

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Course: Main Course, Meal Prep
Cuisine: American
Protein: Beef
Cut: Flank Steak, Flat Iron
Prep Time: 1 hour 15 minutes
Cook Time: 1 hour 20 minutes
Total Time: 2 hours 35 minutes
Servings: 4 people


  • 1 pkg ButcherBox Flank Steak or Flat Iron


  • 2 Tbsp grainy mustard
  • 2 Tbsp chives minced
  • 1 Tbsp olive oil


  • ¼ c champagne vinegar
  • 1 Tbsp chives minced
  • ½ tsp kosher salt
  • ¼ tsp freshly ground black pepper
  • 1 tsp grainy mustard
  • ¾ c avocado oil

Oven Roasted Tomatoes

  • 12 oz pkg grape tomatoes halved
  • 2 tsp thyme finely chopped
  • 2 cloves garlic minced
  • 1 Tbsp olive oil
  • ½ tsp kosher salt
  • tsp ground black pepper

Pasta Salad

  • 1 box cooked gluten-free penne pasta
  • 2 ea avocados medium dice
  • 2 c greens (spinach, arugula or spring mix)


  • Mix marinade ingredients together. Rub on flank steak, and let the flank rest at room temperature for 1 hour.
  • Preheat a grill pan over medium heat. Place flank steak on hot pan. Grill for 10 minutes per side, or until a meat thermometer inserted into the thickest part of the flank reads 125°F. Let flank steak rest for 10 minutes before slicing thinly against the grain.
  • Preheat oven to 325°F
  • Mix all ingredients for the tomatoes together. Put tomatoes flesh-side down on wire rack laid on top of baking sheet. Slow roast for 1 hour. Cool to room temperature.
  • Combine vinegar, chives, salt, pepper and mustard in a food processor. Pulse until mixed.
  • On low speed, add avocado oil in a slow, steady drizzle.
  • Toss all salad ingredients including oven roasted tomatoes in salad bowl with vinaigrette. Serve with flank steak and enjoy!
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Emilie Abijanac

Emilie Abijanac is a chef and Manager of the ButcherBox Test Kitchen. She is a graduate of New England Culinary Institute with over 20 years of catering experience in Boston. Emilie was the sous chef for East Meets West Catering and has worked with Kate’s Table and La Fête.