Step 1: Select the sauté setting on the Instant Pot. Add the butter, chopped onion, carrots, garlic powder, salt, and pepper. Sauté, stirring occasionally, until the vegetables are softened and aromatic. Turn off the heat and allow the mixture to rest briefly.

Step 2: Sprinkle in the flour and pour in the vegetable stock. Stir thoroughly to ensure no lumps remain.

Step 3: Add the mustard and broccoli florets. Stir gently to incorporate all ingredients evenly.

Step 4: Secure the lid and set the Instant Pot to pressure cook for 15 minutes.

Step 5: Once cooking is complete, carefully release the pressure and open the lid. Stir in the cream slowly, allowing it to blend smoothly into the soup.

Step 6: Return the pot to sauté mode for a few more minutes. Add the shredded cheese and stir continuously until fully melted and incorporated.

Step 7: Serve warm, garnished with extra broccoli florets, shredded cheese, or a dollop of sour cream as desired.