Step 1

Preheat the oven to 375°F. Peel and dice the potatoes, finely chop the onion, and mince the garlic.

Step 2

Add the potatoes to a large pot of water. Bring to a boil, cooking for 8-10 minutes until fork tender. Strain in a colander. Then, transfer the potatoes to a greased 9x13 casserole dish.

Step 3

While the potatoes are boiling, melt the butter in a large saucepan or pot over medium heat.

Step 4

Add in the onion and salt, and cook for a few minutes until softened. Add in the garlic and cook for a minute. Then, stir in the flour.

Step 5

Slowly pour in the milk while whisking to incorporate.

Step 6

Add in 2 cups of cheese and the sour cream. Stir until melted and incorporated.

Step 7

Pour the cheese sauce over the potatoes. Gently combine until the potatoes are fully coated.

Step 8

Top with the crushed cereal and the remaining 1 1/2 cups of cheddar cheese.

Step 9

Bake for 20 minutes until the cheese is bubbly.