On medium heat, to a pot, add the oil and the butter. When the butter is melted, add the diced onion and cook until it's translucent. Add the garlic, and cook for a minute or until it's fragrant.
Add the sliced mushroom, and season with salt. Cook until the mushrooms are soft (about 3 minutes). Season with black pepper, and Italian seasoning.
Add in the rinsed rice, and the stock and give it a stir.
Cover with the lid, bring to a boil and simmer on the lowest heat possible for 10-12 minutes.
Carefully remove the lid, fluff with a fork, and mix in sliced green onions.
Make sure that you rinse the rice before cooking with it. Wash under running water until it runs clear. And if you have time, you can soak it in water for 10-15 minutes to improve the texture and get out as much starch as possible.
Don't skip the butter. It adds creaminess to the rice and a depth of flavor. If following a vegan diet, use vegan butter or coconut butter.
Don't slice the mushrooms too thin as they will disintegrate and disappear. I recommend a 1/5" thickness.
Any long-grain rice variety works for this recipe. Basmati and jasmine work best. You can use short-grain rice too, but it will have a different texture.
When adding the stock, make sure that the stock does not exceed the level of the rice. You don't need more stock than that.
You can use vegetable or chicken stock.
OPTIONAL: You can stir in more butter in the rice after cooking for extra creaminess.
Store the mushroom rice in the fridge in an airtight container for up to 4 days.
This rice freezes well in a freezer-safe container for up to 3 months. Reheat in the microwave.