Last Shabbat we did not have a minyan. Yet, the Rabbi read the Torah portion from a Chumash, the Haftora without Brachot and Birkat hachodesch. Is this permissible?

ב"ה Shalom We are all used to seeing the routine way of doing things and that is what we are familiar with. But a Rabbi has to know what to do when things are not routine . Your Rabbi did exactly what is prescribed in Jewish law. We do not perform the Torah reading if there is no minyan . However, in order to ensure that the custom of reading the Torah on Shabbat should not be forgotten, the right thing to do is to read from the Chumash without Brachot and also the Haftora without Berachot. Also the Birkat Hachodesh can be said without a minyan. All the best