1 Tablespoon extra-virgin olive oil
2 Tablespoons butter, divided
1 cup sliced brown mushrooms (crimini or baby bella)
1⁄4 cup chopped onion
1 cup kale leaves, stemmed and chopped
Pinch of red pepper flakes
1⁄8 teaspoon salt
Dash of ground black pepper
4 slices of sourdough bread
2 slices of Swiss cheese
In a medium-sized skillet, heat olive oil to medium heat. Add mushrooms and sauté for 3 to 4 minutes. Add onion and cook for an additional 3 to 4 minutes. Add kale and red pepper flakes; sauté until onion is translucent and kale has softened. Season with salt and pepper and remove from heat.
Assemble first sandwich. On one slice of bread layer Swiss cheese and half of vegetable mixture. Top with other slice of bread. Butter the outside of both bread slices using 1 tablespoon of butter. Repeat with second sandwich.
Place bread buttered side down in a medium-sized skillet over medium heat. Let cook for about 3 minutes or until golden. Flip sandwich to the other side and cook for another 1 to 2 minutes or until bread is toasted and cheese has melted.