In a large saucepan, melt 4 tablespoons of the Country Crock. Whisk in the flour, salt, and pepper until smooth. Slowly drizzle in the milk, whisking the entire time to make sure the flour is incorporated. Bring to a boil and cook about a few minutes, until it's thickened slightly. Remove from heat and add cheese. Stir until melted. Stir in Canadian bacon and mushrooms. Add drained macaroni and stir to combine.