Heat olive oil in a pan on medium heat and add the chilli flakes. Using a wooden spoon, coat the flakes in olive oil.
Add in the chopped garlic and saute in the oil until they start to slightly brown.
Add in the onion and cook until translucent. If you are using the anchovy paste - add it in here
Now add in the mushrooms, sauté and allow them to cook down. If it starts sticking to the pan, add a splash of water.
Once the mushrooms have cooked down, add in the orzo and sauté in the pan for a minute before adding in the broth.
Add broth and allow Orzo the simmer on medium-high heat. Stir occasionally to prevent it from sticking to the bottom of the pan.
If you are using Parmesan, add it here.
Add salt and pepper to taste.
Once the orzo has absorbed the broth and is al dente, remove from heat and serve!