Spinach Artichoke Stuffed Portobello

olive oil

medium portobello mushrooms (stems and gills removed)

package frozen chopped spinach (cooked and drained, 10 ounces)

artichoke hearts (drained and chopped, 14 ounce can)

cream cheese (room temperature)

sour cream

Parmesan cheese (grated)

garlic (chopped)

salt and pepper

mozzarella cheese (shredded)