Bring a medium-size pot of water to boil.
Cook pasta according to package instructions.
Drain water from pasta and set pasta aside.
Melt the margarine in the same pot over medium heat.
Add the white rice flour and whisk together. Let the flour cook for about 30 seconds or until it becomes a light golden color.
Add the milk, nutritional yeast, salt, and pepper.
Lower the heat to medium-low and let the sauce thicken, whisking every so often. This might take about 5-8 minutes.
Once the sauce has thickened, add your pasta and stir to coat.
Adjust seasoning if you desire.