To increate PHP memory usage edit the following file:

nano /usr/local/etc/php/7.4/conf.d/php-memory-limits.ini

You can get the details on your PHP ini using

php --ini

and then do a valet restart to load the new configuration change into memory:

valet restart

That should do the trick. Though you never know as I just spent 30 minutes getting Laravel Valet to run again. Even did a hard reset

valet uninstall --force

and had to redo the certificates using

valet secure

as well.

without that the sites refused access having the wrong certificates I guess.

NB https://github.com/laravel/valet/issues/654 and https://stackoverflow.com/q/60039871/460885 for pointers