Step 1

Add small amount of butter or oil to a medium saucepan and heat on medium.

Step 2

Add onion and sauté for a few minutes.

Step 3

Add bacon and fry gently until partially cooked.

Step 4

Add a little more butter and the mushrooms, if using.

Step 5

Gently fry until mushrooms are soft. Remove mixture from pan and set aside.

Step 6

Add 50g of butter to pan and melt.

Step 7

Add flour and stir with a wooden spoon until combined.

Step 8

Cook for 1 minute, being careful not to burn it.

Step 9

Add milk and whisk gently until mixture boils and thickens.

Step 10

Add cheese and stir until melted.

Step 11

Return bacon mixture to pan, stir to combine.

Step 12

Serve with pasta of choice.