Orzo with Caramelized Mushrooms and Wilted Spinach

INGREDIENTS

1 cup

uncooked orzo pasta

4 tbsp

unsalted butter, divided

4 tbsp

extra-virgin olive oil, divided

2 cloves

garlic, minced, divided, or more to taste

1 1/2 cups

sliced button mushrooms

1 cup

coarsely chopped fresh baby spinach, or more to taste

1/2 cup

minced green onions, or to taste

1/2 cup

shredded Parmigiano-Reggiano cheese, or more to taste

salt and ground black pepper