"Spanakopita Mushroom Caps"
fresh baby spinach
large portobello caps
full-flavor olive oil and truffle-infused olive oil
several pinches of spices
1 small clove garlic, minced
a pinch of truffle salt
a pinch of ground white pepper
1/2 teaspoon parsley flakes
shredded mozzarella cheese
Preheat oven to 425ºF. Line a baking sheet with aluminum foil.
Wilt some spinach. I put about half a 5-ounce package of fresh baby spinach into a microwave steamer, covered with a paper towel, working in two batches of just over an ounce each, for 2 minutes. A large amount of fresh spinach contracts to a MUCH smaller amount when cooked.
Pour a little olive oil into a small dish, maybe a tablespoon per large cap. You'll need enough to coat the back of all the mushroom caps, so it depends on how many of those you have; I had two. Choose a full-flavor olive oil if you have it; I also added a bit of truffle-infused olive oil. Add a pinch or two of spices per cap. A Greek blend would be ideal here; I used Spicely All Purpose Seasoning. Use a pastry brush to mix the spices into the oil, then brush over the back of the mushroom caps.
Put the caps gills-up on the baking sheet. If there is stem left, cut it off close to the cap.
After the spinach is wilted, gather it into a loose roll and use kitchen scissors to cut it into small bits in a bowl.
Peel and mince a small clove of garlic. Scrape the bits into the bowl with the spinach.
Sprinkle in a pinch of truffle salt, a pinch of ground white pepper, and about 1/2 teaspoon of parsley flakes.
Add shredded mozzarella cheese. I used about a cup for two mushroom caps; you need to compare the amount of filling to the space inside the caps. The filling sticks together well, though, so you can mound it up. Mix the filling with your fingers to combine the ingredients as evenly as possible.
Put the filling into the mushroom caps, pressing gently to make it stick in place. Bake for 10-15 minutes, until the cheese has melted and the caps are tender.
This recipe tastes very similar to spanakopita or spinach-mushroom pizza, but without the high carbohydrates and gluten from the pastries. If you like those, you will probably like this too.
Spinach is a great leafy green vegetable. If you don't like the flavor of commercial spinach, try cooking it yourself -- it's usually much more edible. It makes an excellent green filling when mixed with other things.
Portobello mushrooms get quite large and have a dark, meaty flavor. (To make this as an appetizer, use small caps instead.) Usually the big caps are sold pre-cleaned. If yours aren't, you'll need to wash and dry them before trying to brush the oil on, because it won't stick to wet caps -- they get slippery when wet. The stems should either be removed or cut short. If they're not, you'll need to do that, but be careful because mushroom caps break easily. The raw stems are edible, so you can just eat them plain if you wish.
This time I did not pre-cook the mushroom caps before adding the filling. The caps didn't shrink as much as usual, but the centers weren't completely done. Next time I might pre-cook them.
Olive oil has many benefits. If you're not a fan of the flavor, you can use the flavorless kind. However, olive oil can be infused with many other exciting flavors, and now is a perfect time to use them, because the oil soaks right into the spongy mushroom caps. You can buy infused olive oil or make your own. I included the least-worst shopping page I could find, but honestly, everything online seems overpriced. Check your local international food store; I only paid a few bucks for my truffle-infused olive oil from a bulk barrel. You can also flavor your own olive oil using hot or cold methods.
For spices, a wide range will work. I used Spicely All Purpose Seasoning, which is similar to the Greek blend that I wanted but didn't seem to have.
Garlic is a nutritious herb. If you don't have fresh garlic, you can use garlic powder.
Truffle salt is just salt -- preferably sea salt -- mixed with tiny bits of dried truffle. (Avoid artificial flavors.) It enhances the flavor of any other mushroom. If you don't have any, use plain sea salt or table salt.
White pepper comes from the same plant as black pepper, just has the outer shell removed. The flavor is a little milder. If you don't have any, plain black pepper is fine.
Mozzarella is a soft white cheese with superb melting ability. If you're not concerned about melting, you can use feta cheese, which is popular in Greek cuisine but crumbles instead of melting. For a dairy-free option, try nut cheese, but bear in mind that it rarely melts well.
EDIT 9/27/20 -- I forgot to add this when we did it, but the spinach-cheese stuffing also works well if you add sliced mushrooms to it. We made quesadillas with that, using the other half of the spinach package, and they were delicious.