Preheat oven to 400°F + line a sheet pan with foil

Wipe 2 mushrooms with a damp paper towel, remove stems + using a spoon, scoop out the dark gills; place on sheet pan bottom-side up, season with salt/pep + drizzle with oil; bake 10 min

Meanwhile, heat 1 tbsp oil in a skillet over medium; crumble tempe, add to skillet + sauté 5-7 min until browned + hot; crumble ¼-½ the cheese into 'tempe'

Divide filling between mushrooms; bake 10-12 min until cheese is softened; garnish with freshly chopped scallions