Jack is Cooking Fettucini Alfredo

tonight i am cooking fettuccini alfredo. here is an approximate list of ingredients in case you want to make it to. for instructions, watch the video

2 tablespoons butter (or olive oil)
1 onion
2-3 cloves garlic
1 cup half n half (or heavy cream)
1 cup parmesan cheese
salt and pepper
3/4 cup frozen peas