Cook your sausage over medium heat in a large skillet. Drain excess fat.

While your sausage is cooking, squeeze out as much excess moisture from the spinach as possible.

In a medium sized bowl, combine the sausage, spinach, cream cheese, parmesan, garlic powder, onion powder, black pepper, and optional sage/thyme. With a rubber spatula mix together until fully combined.

Refrigerate mix until ready to use.

Preheat the grill to 275 degrees F.

Wash the mushroom caps thoroughly and lay on paper towels to dry.

Using a butter knife, stuff the mushrooms with the filling. You can shape the filling into a small dome on top of each mushroom.

When the grill is at temp, arrange the stuffed mushrooms directly on the grill grate.

Let the mushrooms cook for about 30 minutes. The mushrooms should be shrunken down due to loss of moisture, and the filling should be hot.

Take mushrooms off the grill and serve immediately.