As a single millennial living alone in one of the most expensive cities in the world, feeding myself can be hard.

There are so many bad eating habits I’m prone to falling into without adult supervision (yes, I do realise I AM an adult, but I am still slightly in denial).

Nightly Uber Eats, subsisting on Mi Goreng, cereal, or ice cream for dinner, buying lunch at work everyday, drunk Maccas, hungover Maccas, Wednesday night Maccas… the list is endless.

A list that, time after time, results in me feeling sluggish and well, gross, as well as getting to the end of the week and realising I have…no money.

Enter “vegetable/protein of the week” – a thrifty food shopping game I’ve adopted into my mid-20s which has quite literally changed my life.

Here's what it entails:

Every Sunday, I'll choose a single protein or vegetable and three different cuisines.

Then, I'll buy my chosen meat or veg in bulk.

I'll then scout out (or invent, if I'm feeling creative) three recipes based on my chosen cuisines as well as what I already have kicking around in the fridge and cupboard. Sometimes, I'll need to grab one or two extra ingredients, but it won't set me back too much.

Then, the big, messy Sunday evening meal prep begins.

On a good week, this means I spend under $20 at the supermarket given I already have a few staples, which we'll get to later.

Here's how it's helped me so much:

I never throw food away

Nothing grinds my gears more than wasting food. I've been brought up by my frugal foodie mum to use up whatever's in the fridge before heading to the shops.

Planning my meals ahead, and only buying one main ingredient means I never find slimy rotting spinach leaves in the bottom of the fridge. Even if I did, I'd probably have to use them up somehow - never wasting food is too far ingrained in me.

I actually enjoy it

Look, I'm a bit of a w*nker when it comes to food. I love cooking, and one of my favourite things to do when I'm feeling down is flip through cookbooks and look at the pictures for inspiration.

Pretending I'm Nigella Lawson is my version of planning imaginary holidays for stress release.

This means I get a little kick when I turn a couple of eggplants into three glorious gourmet meals that have my work colleagues asking: "where did you get THAT?"

I can smugly say "I made it" and await my trophy for, you know, being a fully-functioning adult in at least one aspect of my life.

Plus, I'm never bored by my meals. Even though I'm eating the same base vegetable or protein all week, I always alternate, and my three cuisines trick avoids it tasting the same.

I never feel guilty when I treat myself

If I come to the end of the week and I've eaten all my meals (which rarely happens because I always cook in big batches) I don't feel guilty splurging on a cheeky Uber Eats or heading out to dinner with friends.

I almost always have a spare meal kicking around which I can freeze and eat the next week, so I know it's never going to be more than one night a week I'll spend money on eating out or takeaway.

And the biggest win: I'm saving a lot on frivolous food purchases.

I stick to healthy, nourishing meals like curries and stir fries or protein-filled salads because I know they'll fill me up. This way I avoid the end-of-day munchies which in the past has led to grabbing a supermarket sandwich or sushi to eat on the way home from work. The ultimate trap.

I also often choose my protein or vegetable based on what's on special, and always make sure I have the bases to make my favourite go-to meals.

Things I always have in the fridge/cupboard include: Thai red and green curry paste, tomato puree, pesto, herbs and spices, garlic, oyster sauce, soy sauce, honey, eggs, frozen vegetables, tinned tuna, chick peas or lentils and brown rice.

I also don't eat much meat because it can be expensive, but when I do, I opt for turkey or chicken mince and frozen salmon fillets.

Chicken thighs on special are my favourite kind of treat.

Recipe ideas:

This week, my protein was tofu (roughly $2.50 for a packet from Woolies) and my three cuisines were Moroccan, Chinese and Thai.

I bought two 300g packets, cut them up and split them into three portions.

One load was roasted in the oven with olive oil and Moroccan spice. I had this with baby spinach and chickpeas in a salad for three lunches.

With the second load of tofu, I made a Thai curry with red curry paste, eggplant, garlic, basil, coriander and coconut oil mixed with low-fat Greek yoghurt (a healthy alternative to coconut milk or cream I picked up from a food blog - revolutionary). This was dinner for two nights, lunch for one, and I have a bit leftover. (It can be padded out easily with brown rice).

The third portion I stir fried with frozen vegetables, chilli, garlic, soy sauce, oyster sauce, a tiny bit of honey and sesame seeds. This has been dinner for three nights, and I still have leftovers.

Last week, it was chicken mince, and Italian, Thai and Moroccan.

I made a chicken mince zucchini noodle pesto salad with one load, a Thai red curry with one (using the same recipe as tofu above), and split the third to make six Moroccan patties (Morroccan spice, chickpeas, garlic, spring onion and egg) and Thai patties (lime juice, spring onion, fish sauce, red curry paste, chilli, garlic, coriander), which ate with a simple spinach and avocado salad.

Often, my vegetable of the week will be sweet potato (cheap and filling). I'll roast one with Moroccan spice to put in a salad with chick peas, baby spinach and sundried tomatoes, mash another as a bed for a piece of fish that I already have in the freezer and turn the third into a curry, using chickpeas and whatever spices I have lying around in the cupboard.

You get the idea.

It's not perfect, and I'm still working out the maths behind it, which can be...difficult.

You see, I always aim to make three meals out of my protein or vegetable that I can split up into about eight Tupperware containers, alternating for lunch and dinner throughout the week. But sometimes I'll invent something truly amazing and accidentally eating it all in a few days.

...But then I get to experience the joy of coming up with a bonus vegetable of the week.

So really, you just can't lose.