01 - Set the Instant Pot to Sauté. Add butter and let melt. Add diced onion and sauté for 2–3 minutes until softened. Stir in minced garlic and cook for 30 seconds until fragrant.
02 - Sprinkle flour into the pot and cook, stirring constantly, for 1 minute to form a smooth roux and eliminate raw flour taste.
03 - Gradually pour in vegetable broth while whisking continuously to prevent lumps and ensure smooth incorporation with the roux.
04 - Add broccoli florets and grated carrot to the pot. Season with paprika, nutmeg, salt, and pepper. Stir well to combine.
05 - Seal the lid and set vent to sealing position. Cook on Manual High Pressure for 5 minutes.
06 - Perform a quick pressure release by carefully moving the valve to venting. Open lid once all pressure has released.
07 - Use an immersion blender to purée the soup to desired consistency—completely smooth or slightly chunky according to preference.
08 - Set Instant Pot to Sauté Low. Stir in milk and heavy cream. Gradually add shredded cheddar cheese, stirring constantly until fully melted and incorporated.
09 - Taste soup and adjust salt and pepper seasoning as needed. Serve hot, garnished with additional cheddar cheese or fresh herbs if desired.