Mushroom Risotto in Instant Pot

Ingredients

• 4 Tbsp. Olive oil
• 4 Tbsp. butter, divided
• 1 medium onion, diced
• 2 cloves garlic, minced
• 8 oz. portabella mushrooms, sliced
• 1 1/2 cups arborio or risotto rice
• 4 cups chicken broth
• 1-1 1/2 cups fresh grated parmigiano-reggiano cheese