In a large pot, melt butter over medium-high heat.

Add chopped onion, sliced leeks, salt and pepper and saute until onion begins to brown.

Add sliced potatoes and cover with chicken broth (potatoes should be all or mostly covered with liquid).

Bring to a boil, reduce heat and simmer until potatoes are soft (about 30 minutes).

Mash potatoes with a potato masher to desired consistency and mix thoroughly with liquid. Add cream, corn, and bacon and mix thoroughly.

Bring mixture back to a simmer and simmer another 10 minutes. Serve with croutons.