1. Roast the Mushrooms:
- Preheat your oven to 400°F (200°C).
- Toss the sliced mushrooms with 1 tablespoon of olive oil, salt, pepper, and thyme (if using).
- Spread the mushrooms in a single layer on a baking sheet and roast for about 15-20 minutes, or until they are golden and slightly crispy around the edges. Remove and set aside.
2. Caramelize the Onions:
- While the mushrooms are roasting, heat the remaining tablespoon of olive oil in a skillet over medium-low heat.
- Add the sliced onions and cook, stirring occasionally, for about 10-15 minutes, or until they are soft and caramelized. Season with a pinch of salt and pepper. Remove from heat and set aside.
3. Assemble the Sandwiches:
- Spread softened butter on one side of each slice of bread.
- On the unbuttered side of two slices of bread, layer a generous amount of shredded Gouda, followed by the roasted mushrooms and caramelized onions.
- Add another layer of Gouda on top, then cover with the other slice of bread, buttered side facing out.
4. Cook the Grilled Cheese:
- Heat a skillet or griddle over medium heat. Place the sandwiches in the skillet and cook for 3-4 minutes on each side, pressing gently with a spatula, until the bread is golden brown and crispy, and the cheese is fully melted.
5. Serve:
- Slice the sandwiches in half and serve immediately while the cheese is gooey and melty.
This Grilled Cheese with Gouda, Roasted Mushrooms, and Onions is a rich, savory sandwich that takes comfort food to new heights. Perfect for lunch or a cozy dinner, it’s a simple yet gourmet twist on the classic grilled cheese!