Set your instant pot to sauté and melt the butter. Add the onions, carrots, celery, garlic, ½ tsp kosher salt, and ¼ tsp fresh ground pepper.

Sauté for 5 minutes until the onions are soft but not starting to brown.

Add the vegetable broth and the broccoli.

Reset the Instant pot and secure the lid, setting the pressure release valve to the close or sealing position.

Select pressure cook or manual setting and set the cooking time for 1 minute on high pressure.

While the soup is cooking, mix together the half and half, cornstarch, and hot sauce, stirring to combine.

Once the cooking cycle is complete natural release for 5 minutes, then move the pressure release to the vent to release the remaining pressure from the pot.

Carefully remove the lid and reset or turn off the instant pot, then set it for sauté.

Stir the half-and-half mixture to recombine as the cornstarch has settled. Add the mixture to the pot along with the grated cheddar cheese, and stir so it is mixed well.

Allow the soup to come up to a simmer and cook for 1-2 minutes, stirring occasionally. The soup should have thickened slightly.

Press cancel or turn the unit off. Season with Kosher salt and fresh ground pepper to taste.

Serve with additional hot sauce if desired.