Wipe the mushrooms with a damp cloth to clean them, then gently remove the stems and finely dice those stems while leaving the caps whole. The caps should stay intact, and clean fresh mushrooms often make a faint squeak when the surface is properly dry.

Melt the butter in a medium skillet over medium heat, then cook the diced stems with the minced garlic for about 3 minutes. The mixture should soften and smell deeply savory, with no raw garlic harshness left.

Add the chopped sage along with salt and pepper, cook for 1 more minute, and set the pan aside to cool for 5 minutes. You’re looking for a fragrant mixture that smells buttery and herbal rather than sharp.

Heat the oven to 350 °F and grease a large glass or ceramic baking dish. A glass or ceramic dish helps the mushrooms cook evenly without browning the bottoms too aggressively.

Mix the softened cream cheese, grated cheddar, and cooled mushroom mixture in a large bowl with a rubber spatula. The filling should look thick, creamy, and evenly speckled with the sautéed stems and herbs.

Fill each mushroom cap with the cheese mixture, pressing it into the cavity, then arrange the mushrooms in the prepared dish and bake for 15 to 20 minutes. They’re ready when the tops are bubbling and melted and the mushrooms feel tender.

Let the mushrooms cool for 10 minutes, then finish with chopped sage before serving. The filling will settle slightly as it rests, making the mushrooms easier to pick up and eat.