1.   Continue whisking until the mixture looks smooth and creamy.

2.   Add peas and a tablespoon of water if mixture looks dry.

3.   Add some of the cooking water if the mixture looks dry.

4.   Add the butter and toss to coat, adding some of the pasta water if the mixture looks dry.

5.   For a moment, the mixture looked curdled.

6.   If the mixture looks dry, add some of the reserved cooking liquid.

7.   If the mixture looks dry, add some of the cooking liquid.

8.   If mixture does not look moist and creamy, add a little more of the milk and cheese.

9.   Mixture will look dry.

10.   Mixture will look like cornmeal.