Sirloin Steak & Sweet Potato Fries With Mustard Sauce

What You’ll Need:

For the Steak & Fries

• 1–2 lbs grass-fed sirloin steak

• 2 medium yellow onions, sliced

• ½ stick butter (divided)

• Salt & pepper to taste

• 1–1.5 lbs sweet potatoes, sliced into fries, or 1 lb bag frozen sweet potato fries

• 3 tbsp olive oil

For the Mustard Sauce

• 2 cups mustard (sweet & spicy, stoneground, yellow, or your favorite blend)

• ½ cup apple cider vinegar (start with ¼ cup, add more to thin as desired)

• 5 tbsp brown sugar or blackstrap molasses

• 2 tbsp hot sauce (tangy types like Frank’s work well)

• 2 tsp Worcestershire sauce

• 1 tsp vanilla extract

• Pepper to taste

Let’s Cook:

1. Caramelize the Onions

   • Heat a skillet over medium heat with ¼ stick of butter. Add sliced onions and cook slowly, stirring occasionally, until deeply golden and sweet, about 30–45 minutes.

2. Prepare the Sweet Potato Fries

   • Preheat oven to 425°F. Toss sweet potato fries with olive oil and a pinch of salt.

   • Roast for 20–30 minutes, flipping once halfway through, until tender and crisp. (If using frozen fries, follow package directions.)

3. Make the Mustard Sauce

   • In a bowl, whisk together mustard, apple cider vinegar, brown sugar/molasses, hot sauce, Worcestershire, vanilla, and pepper. Adjust thickness with more vinegar if desired. Set aside.

4. Cook the Steak

   • Pat thawed steaks dry with paper towels and season generously with salt and pepper on both sides.

   • Grill over high heat or sear in a heavy frying pan with a high-temp oil (like grapeseed) until your preferred doneness.

   • Rest steaks for 5–10 minutes, then slice into ¼-inch thick strips.

5. Assemble & Serve

   • Arrange sweet potato fries on a platter, top with caramelized onions, layer on sliced steak, and drizzle generously with mustard sauce.

   • Serve extra sauce on the side for dipping.