To test your filets for doneness, gently press your finger (or the tip of a knife if it's too hot) onto the top center or thickest part of the filet - if it begins to flake or separate then it is done cooking. If you overcook the filets, they will be dry and overly flaky. You may also use an instant read thermometer to check for doneness, salmon is finished when it reaches 125-135F in the thickest part of the filet.