Heat a medium pot over med; add ½ pack bacon + cook, flipping frequently, until browned + cooked through, 4-6 min; let cool slightly + crumble into bite-size pieces; remove bacon + reserve fat

Dice onion; heat bacon fat + 1 tbsp oil over med; cook onions 3-5 min until softened

Meanwhile, peel + dice both potatoes; add 3-4 cups water + potatoes to onion; bring to a boil + cook 9-11 min until potatoes are tender

Add 4-6 tbsp creme fraiche + ½ cup cheese to soup; stir until melted 1-2 min; in batches puree soup until smooth; return to pot, taste + season with salt/pep; divide soup to bowls then sprinkle each with crumbled bacon + 2 tbsp cheese