Prepare the ingredients: cut the zucchini into thick, at least 1/2-inch (1.5 cm) slices (don't slice it too thin!) or half circles (depending on the size of the zucchini). Finely chop garlic with a knife (and not a garlic press). Zest the lemon (preferably on a Microplane).
Heat olive oil and butter over medium heat in a large frying pan. When hot add the zucchini in a single layer (if it doesn't fit in a single layer it can overlap a little bit but you shouldn't have multiple layers).
Cook until browned at the bottom then turn over and cook until the other side is browned making sure it's still crunchy and not too soft.
Add the garlic, chili flakes, and lemon zest to the pan. Cook for 30 seconds over lowest heat or until the garlic is fragrant. Make sure to not burn the garlic.
Season the zucchini with lemon juice, salt and pepper.
Transfer to a plate and sprinkle with finely grated cheese (preferably on a Microplane).
Enjoy!