Heat a fry pan with a medium heat and add in the walnuts, mix continuously for 2 to 3 minutes or until the walnuts are lightly pan-roasted, then remove them from the pan and set aside

Add the olive oil into a large bowl, along with the sherry vinegar, Dijon mustard, and grated garlic, then season with salt & pepper and whisk everything together until well mixed

Drain the cans of lentils into a colander and rinse under water, then shake off all the excess water, transfer the lentils into the bowl with the dressing, and gently mix together until all the lentils are coated in the dressing

Add in the finely diced apple, chopped red onion, chopped celery, crumbled goat cheese, and chopped parsley, then crumble in the pan-roasted walnuts, and season everything with salt & pepper, gently mix together until well mixed

You can serve this lentil salad at room temperature or even chilled, as it will hold for up to 3 to 4 days in the fridge in an airtight container, enjoy!