If you have a food processor, pulse garlic until minced then add the basil and lemon zest and pulse until finely chopped. If you do not just mince everything by hand first separately and then together.
Heat olive oil in a large skillet. Add breadcrumbs and toss to evenly coat in olive oil. Cook over med-low heat, tossing frequently until golden brown, about 5 minutes. When just about done mix in the parmesan and a dash of salt and pepper.
Let breadcrumbs cool on a paper towel lined plate.
Mix everything together just before eating - once mixed the gremolata should be stored in the fridge and will keep 3-4 days. To re-toast the gremolata, heat up a little extra olive oil in a pan and cook over low heat for 5-7 minutes.
Notes
You can make this a day or two in advance - once you have toasted and cooled the breadcrumbs keep them in an airtight container on the counter and keep the basil lemon mixture in the fridge, mix everything together just before eating.
Recipe by Eat Some Wear Some at https://eatsomewearsome.com/basil-lemon-gremolata/