This Keto Blue Cheese Crusted Filet with Mashed Cauliflower and Balsamic Mushrooms is a great low-carb steak dinner for 2!

This Keto Blue Cheese Crusted Filet with Mashed Cauliflower and Balsamic Mushrooms is sponsored by Castello Cheese. Thank you for supporting the brands that make CIK recipes possible
Is there anything better than a steak dinner? We’ve been making steak a lot lately, trying out different cuts and cooking methods, and this Keto Blue Cheese Crusted Filet with Mashed Cauliflower and Balsamic Mushrooms is currently #1 and we don’t see it falling off that rank any time soon.
This filet is literally in the top three steaks we’ve ever had, of all time.
To level up the steak, we made an insanely good crust with Castello Danish Blue, crushed pork rinds to mimic panko crumbs and sauteed shallots and garlic along with some fresh herbs. The sharp blue cheese taste with a hint of nuttiness from the Castello Danish Blue went perfectly with the rich steak.

How to make a Keto Blue Cheese Crusted Filet
We started the steak in the cast-iron skillet, getting a nice seared crust and cooking most of the way through before topping it with the cheese mixture and popping it under the broiler. The pork rinds help bind the cheese mixture together so that it doesn’t just melt and creates the perfect crust on top of the filets. The filets literally melted like butter; so tender.
To complete the meal, we served it with our self-proclaimed famous mashed cauliflower (we worked on the recipe until it was perfect for our cookbook!) and tangy balsamic mushrooms. If you want to keep this meal to one-pan, like how the recipe is written, you may want to reheat the mashed cauliflower just a touch before serving, or you can simply use a different pan or pot and have it done at almost the same time as the steak. Totally up to you!

We really love Castello Cheese. You may remember our Spicy Bacon Gouda Dip using the brand’s Gouda cheese. Castello Cheese has a variety of options with distinct tastes, flavors, and textures. There’s something for everyone.
You can find Castello Cheese in your specialty cheese aisle. Search for a store near you here.
📖 Recipe

Blue Cheese Crusted Filet with Mashed Cauliflower and Balsamic Mushrooms
Ingredients
- 2 6-oz filets
- 1 tablespoon unsalted butter
- 1 shallot thinly sliced
- 1 clove garlic minced
- ¼ cup pork rind crumbs 0.5-oz
- 1 tablespoon fresh parsley minced
- 3 ounces crumbled Castello Danish Blue Cheese
- ¼ teaspoon salt
- ⅛ teaspoon freshly ground black pepper
Mashed Cauliflower:
- 2 tablespoons unsalted butter
- 1 clove garlic
- 10 ounces diced cauliflower florets
- ½ cup heavy cream
- Salt and pepper to taste
Mushrooms:
- 4 ounces cremini mushrooms thinly sliced
- 1 tablespoon unsalted butter
- .5 tablespoon balsamic vinegar
- Salt and pepper to taste
Instructions
- To make the mashed cauliflower, melt the butter in a 10” or larger cast-iron skillet over medium heat. Add the garlic and cook for 30 seconds until fragrant. Add the cauliflower and heavy cream. Cover and cook for 10 minutes until soft. Transfer the cauliflower, minus any leftover liquid, to a blender, food processor or use an immersion blender to puree the mixture until smooth. Add in a bit of the leftover liquid to thin, if needed. Season liberally with salt and pepper, to taste. Transfer the mashed cauliflower to a bowl and set someplace warm. Wipe out the skillet.
- Season the filets with salt on both sides. In a medium bowl, combine the minced herbs, Castello Danish Blue, pork rind crumbs, salt, and pepper, set aside.
- Heat 1 tablespoon of butter in the skillet over medium heat. Add in the shallots and cook for 5 minutes until softened. Add in the garlic and cook for another minute. Transfer to the bowl with the blue cheese mixture. Wipe out the skillet.
- Preheat the oven broiler to high. Heat the avocado oil in the skillet over medium-high heat and sear the steaks for 5-7 minutes per side.
- Top each steak with the blue cheese mixture and transfer to the oven. Broil for 5 minutes until the crust is golden. This will result in a medium-rare filet. Remove from oven and let rest while you make the mushrooms.
- Without wiping out the skillet, add the butter to the pan over medium heat. Add the mushrooms and cook for 5-7 minutes, until soft. Deglaze the pan with the balsamic vinegar and season to taste.
- To serve, divide the cauliflower between two plates. Top with mushrooms and steak. Serve immediately.
Nutrition
Nutritional values are estimates only and do not include carbs from sugar alcohols.

Jedidja says
This looks amazing! Can't wait to try it for my wife's birthday 🙂
One question regarding the steaks - in the post it says "We started the steak in the cast-iron skillet, getting a nice seared crust and cooking most of the way through" but in the instructions, I can only see putting the steaks directly in the oven. Am I missing something? I'm guessing sear for a few minutes on each side?
Cast Iron Keto says
Hi! Yes, step 4 in the instructions have you searing the steaks over medium-high for 5-7 minutes per side before transferring to the oven.
Jedidja says
I don't know how I missed that the first time 🙂 This turned out really well!
My oven's broiler must be a bit on the hot side. For 7oz steaks and the rack in the second highest position, five minutes on high made the steaks turn out medium well. Easy enough to fix next time 🙂