First clean your clams. Allow them to soak in a bowl of cold water for 20 minutes. Then take each clam and use a soft brush or wet towel to clean the outside shell. A good tip is to not pour out the clams and water, instead remove them one by one. You can then allow to to sit in another bowl while you prepare the rest of the dish.
In a large skillet, drizzle olive oil and add chopped onion. Allow onion to cook for about 5 minutes until it begins to caramelize. Then add garlic and red pepper flakes and continue to cook for another 3 minutes until the garlic begins to caramelize. .
Add flour and use a spoon to cook the flour into the olive oil. It should form a paste. Next add white wine and a cup of water and salt and pepper and increase heat. Continue to stir so all the flour is cooked off and sauce begins to thicken.
Add chopped parsley and clams and lower flame so sauce is simmering. Allow clams to cook until they begin to open and remove clams as they open. When all clams are removed, you can either continue cooking the sauce to reduce more. It should lightly coat the back of a spoon.
When done, place clams in a bowl and pour sauce over. Garnish with extra parsley.
This recipe is enough for 4 tapas, which is about 6 clams per person. You can adjust the amount of clams per person as needed.