Vegan Brussels Sprout Gratin

Brussels sprouts (trimmed and halved)

and 1/2 tbsp olive oil (divided)

shallots (thinly sliced)

garlic (minced or grated)

salt

batch cashew mozzarella ((salt and garlic excluded; prepared up to the cooking step))

panko-style breadcrumbs ((gluten-free if needed; check labels for dairy ingredients))

dried oregano

dried thyme

ground black pepper

nutritional yeast ((optional))