Grilled Filet with Creamy Mushroom & Greens Sauce
Tender grilled filet mignon topped with a rich, garlicky mushroom cream sauce with baby greens folded right in. This is steak night, Amy-style: plenty of protein, plenty of vegetables, loads of flavor, and absolutely nothing about it feels like “diet food.”
Serve it alongside my Cheesy Cauliflower Bake for a seriously satisfying dinner.
SERVES 2 | PREP 10 min | COOK 20 min
What You’ll Need
For the Filets
2 filet mignon steaks
Olive oil
Kosher salt
Freshly cracked black pepper
Garlic powder
For the Creamy Mushroom & Greens Sauce
8 oz mushrooms, sliced
¼ cup finely diced Vidalia onion
2 cloves garlic, minced
1 Tbsp butter or olive oil
1 tsp Worcestershire sauce
⅓–½ cup heavy cream
1 Tbsp cream cheese
1 generous handful chopped baby spinach and/or kale
Freshly cracked black pepper
Salt, to taste
How to Make It
1. Prep the steaks.
Remove the filets from the refrigerator while you prep the vegetables. Pat them dry, lightly coat with olive oil, and season generously with salt, black pepper, and garlic powder.
2. Start the mushroom sauce.
Heat butter or olive oil in a skillet over medium-high heat. Add the mushrooms and let them cook until they release their moisture and begin to get beautifully golden around the edges.
3. Build the flavor.
Add the diced Vidalia onion and cook until completely softened. Stir in the garlic and cook for another 30 seconds or so, just until fragrant.
4. Make it creamy.
Add the Worcestershire, heavy cream, and cream cheese. Reduce the heat and stir until the cream cheese melts into the sauce. Let everything gently simmer and thicken for a few minutes.
5. Add the greens.
Toss in a generous handful of chopped baby spinach and/or kale. Stir until the greens wilt into the mushroom sauce. Continue simmering uncovered until the sauce is thick and creamy. Finish with plenty of freshly cracked black pepper and salt to taste.
6. Grill the filets.
While the sauce simmers, grill the steaks over high heat until they reach your preferred doneness. For medium-rare, I like to pull them from the grill around 120–125°F and let carryover heat finish the job while they rest.
7. Rest and serve.
Let the filets rest for 5–10 minutes. Serve whole or slice across the grain, then spoon that creamy mushroom and greens sauce right over the top.
Amy’s Notes
Brown those mushrooms. Don't rush them. Letting the mushrooms actually develop some color adds so much more flavor than simply cooking them until they're soft.
The greens were originally a what-if? 😂 I tossed a handful of chopped baby spinach and kale into the sauce on a whim—and immediately decided they belonged there. They add color, texture, and another serving of vegetables without taking anything away from the rich, creamy steakhouse feel.
Don't drown the steak. Filet mignon deserves to taste like filet mignon. Spoon enough sauce over the top to get mushrooms and greens in every few bites, then serve extra sauce alongside if you have it.
Make the whole plate. I served this with my Cheesy Cauliflower Bake, and the combination was ridiculous. Since the cauliflower already brings plenty of cheesy richness, I intentionally kept the steak sauce simple—cream, mushrooms, garlic, greens, and just enough cream cheese to give it body.
