Preheat oven to 350 degrees.

Spray a 2 qt baking dish with nonstick cooking spray.

Set aside the baking dish.

Heat olive oil in a large nonstick skillet over medium heat.

Add chopped yellow onion, minced garlic, sliced cremini mushrooms, kosher salt, and crushed red pepper to the skillet.

Cook, stirring occasionally, until the onion softens (approximately 10 minutes).

Add chopped kale in batches, stirring until wilted after each addition.

Stir in flour and cook for 1 minute.

Gradually add chicken broth and half-and-half, stirring constantly until thickened (approximately 5 minutes).

Add 1/2 cup of shredded Gruyere cheese and cooked wild rice, stirring to combine.

Spoon the mixture into the prepared baking dish.

Sprinkle with the remaining Gruyere cheese.

Bake until bubbly and the cheese melts (approximately 25 minutes).

Serve immediately.