First, create a universe. It needn't be
infinite; you only have to ensure that you'll have
enough space to work in.
The noise will settle down to a background hum after the first few microseconds.
You will need:
1 medium-sized sun
4.5 billion years
A standing mixer
Preheat the oven to 350.
In a superheated ball of gas, fuse hydrogen for heat and light.
Stir in carbon, hydrogen, oxygen and nitrogen in your preferred configurations.
Season to taste with trace elements.
Mix well, striking occasionally with lightning.
Once you've got evolution started,
don't worry about the mess; these things have a way of self-limiting.
Grease an 11"x9" pan. Avoid large asteroid strikes if possible, but remember:
mass extinctions are an inevitable part of the process.
Pour the batter into the pan as evenly as you can. By now,
your planet should have evolved intelligent life.
This is a good time to send out your invitations,
unless they are bad conversationalists.
Bake for 30 minutes, or until a knife inserted into the middle
comes out clean. Serve with a glass of wine,
so you can toast the first clumsy ships
sparking off into the cosmos.