• Place the Instant Pot on the saute function. Add 1 tablespoon of butter, chopped onions, and garlic. Cook for 2-3 minutes until the onions are translucent and fragrant.
• Add the chicken broth, broccoli florets, salt and pepper to taste to the pot. Stir to combine.
• Place the lid on the Instant Pot and seal. Cook for 4 minutes on Manual > High-Pressure Cooking.
• While the soup cooks, melt 1 tablespoon of butter in a small bowl. Add the flour to the butter and stir.
• When the pot indicates it has finished, quick release the steam and place it on the saute function.
• Open the pot and add the heavy whipping cream and shredded cheddar to the pot.
• Scoop out a couple of tablespoons of the soup and add it to the bowl with the melted butter and flour. Stir and add the mixture back to the pot. This will thicken up the soup.
• Place the Instant Pot on saute for a few minutes until the cheese has melted. 
• Serve in bowls.

Stovetop

• Add 1 tablespoon of butter, chopped onions, and garlic to a large pot or Dutch oven on medium-high heat. Cook for 2-3 minutes until the onions are translucent and fragrant.
  
• Reduce the heat to medium and add the broth, broccoli, salt, and pepper to taste to the pot. Cover and cook for about 5 minutes or until the broccoli is tender.
• While the soup cooks, melt 1 tablespoon of butter in a small bowl. Add the flour to the butter and stir.
• When the broccoli is tender, add the heavy whipping cream and shredded cheddar to the pot.
• Scoop out a couple of tablespoons of the soup and add it to the bowl with the melted butter and flour. Stir and add the mixture back to the pot. This will thicken up the soup.
• Remove the pot from the heat. Allow a few minutes for the cheese to melt and the soup to thicken.
• Serve in bowls.