Cut potatoes into 1/8" thick slices. Halve large potatoes first.

Cut onion into about 1" squares.

Melt all grease in large pan.

Add potatoes to hot grease. Heat on med-high.

Season with salt and pepper.

Once potatoes start to soften add onion.

Continue to heat until no potatoes are soft.

Increase heat to high for the last couple minutes.