Step 1
Set Instant Pot to "Sauté" setting. Cook bacon, stirring occasionally, until crisp, 10 to 12 minutes. Using a slotted spoon, transfer bacon to a plate, leaving fat in pot. Add onion and cook, stirring occasionally, until softened, 5 to 7 minutes. Stir in flour, garlic, and thyme and cook, stirring occasionally, until fragrant, 1 minute more. Pour in broth and stir until flour is dissolved, about 30 seconds.
Step 2
Add potatoes, half-and-half, 1 1/2 teaspoons salt, and 1/4 teaspoon pepper and stir to combine. Cover pot, then set to Pressure Cook on High and set timer for 8 minutes. Slow release pressure.
Step 3
Uncover pot and stir in sour cream. Using an immersion blender, blend until some chunky bits of potato remain. Alternatively, you can use a standard blender to blend about half of soup and return to pot.
Step 4
Divide soup among bowls. Top with more sour cream, bacon, cheddar, and chives.
