The intention is to show a widget on the dashboard, that may or may not be attention demanding. That depends on a database query with our conditions, and its result.
In this showcase, we're listing the Menu Items that were marked unavailable by the cooks, so that other staff can act on it.

Because of that, we want the widget to be very "flashy", so that it demands the attention of the user.
Once they restock and mark as available, they will not be on the query, and the widget will be collapsed and be discreet.

Let's start.
Implementation
First, we run php artisan make:filament-widget
, and will be asked:
Widget name:
UnavailableItems
Type of Widget:
Table
Create in a resource: No - leave blank.
Where to create? In the Panel
We get the Widget class created. These are the next steps:
Define the Query and be able to get the count, to be in Alert mode or not.
Define columns, including a URL to visit the record.
Keep pagination at a small amount - it only paginates if that amount is surpassed, to keep the UI uncluttered.
Create the view file, and add contents.
Find below the code.