Portobello Croque Monsieur

Elevate your sandwich game with this indulgent Portobello Croque Monsieur, a creative twist on the classic French favorite. In this recipe, meaty portobello mushroom caps replace traditional bread, offering a deliciously gluten-free and low-carb alternative while adding a rich, earthy flavor. Layers of savory roasted mushrooms, thinly sliced ham, creamy homemade béchamel sauce, and nutty Gruyère cheese come together in a broiled masterpiece that’s both satisfying and elegant. This dish is perfect for a sophisticated brunch, a unique lunch, or a hearty dinner option. Garnished with optional fresh thyme, it’s a restaurant-quality meal you can easily make at home in under 40 minutes. Whether you’re a mushroom lover or searching for a gourmet comfort food recipe, this Portobello Croque Monsieur is sure to impress.

Nutriscore Rating: 63/100

Prep Time:15 mins

Cook Time:25 mins

Total Time:40 mins

Servings: 2

Ingredients

• 4 pieces Large portobello mushroom caps
• 2 tablespoons Olive oil
• 0.5 teaspoons Kosher salt
• 0.25 teaspoons Black pepper, freshly ground
• 2 tablespoons Butter, unsalted
• 1 tablespoon All-purpose flour
• 1 cup Whole milk, warmed
• 1 teaspoon Dijon mustard
• 1.5 cups Gruyère cheese, shredded
• 4 slices Thinly sliced ham
• 1 teaspoon Fresh thyme leaves (optional)

Directions

Step 1

Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or foil.

Step 2

Clean the portobello mushroom caps by wiping them with a damp paper towel and removing the stems and gills using a spoon. Place the mushrooms gill-side up on the baking sheet.

Step 3

Brush the mushrooms with olive oil on both sides and sprinkle with kosher salt and black pepper. Roast in the preheated oven for 10–12 minutes until softened. Remove and set aside.

Step 4

While the mushrooms roast, make the béchamel sauce. In a small saucepan, melt the butter over medium heat. Once melted, whisk in the flour and cook for 1 minute to form a roux.

Step 5

Gradually whisk in the warmed milk, ensuring no lumps form. Stir constantly for 3–4 minutes until the sauce thickens. Remove from heat and whisk in Dijon mustard and 1/2 cup of the shredded Gruyère cheese until smooth. Set the sauce aside.

Step 6

Turn the oven to broil on high. Pat the roasted mushrooms dry with a paper towel to remove excess moisture. Spread a thin layer of béchamel sauce on the gill side of two mushroom caps.

Step 7

Layer each béchamel-coated cap with 2 slices of ham and sprinkle with 1/4 cup of shredded Gruyère. Top with the remaining mushroom caps, gill-side down, to form a 'sandwich.'

Step 8

Spread a generous amount of béchamel sauce on top of each assembled sandwich and sprinkle with the remaining shredded Gruyère cheese.

Step 9

Place the sandwiches back on the baking sheet and broil for 3–5 minutes, or until the cheese is bubbly and golden brown.

Step 10

Garnish with fresh thyme leaves, if desired, and serve immediately.

Nutrition Facts

Serving size	(1078.7g)

Amount per serving	% Daily Value*
Calories	1576.5

Total Fat 123.7g	0%
Saturated Fat 57.1g	0%
Polyunsaturated Fat 2.7g
Cholesterol 330.0mg	0%
Sodium 3196.7mg	0%
Total Carbohydrate 38.0g	0%
Dietary Fiber 5.6g	0%
Total Sugars 22.0g
Protein 87.5g	0%

Vitamin D 188.0IU	0%
Calcium 1926.7mg	0%
Iron 4.5mg	0%
Potassium 2239.7mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 68.9%

Protein: 21.7%

Carbs: 9.4%