If you're anything like me, from an early age, you made mental lists of your favourite things, and maybe even sorted into the order of how much you liked them. Things like your top 5 chip flavours, TV shows, and friends; and later on, your celebrity crushes, clothing brands, and Hugh Grant rom-coms (About A Boy, thanks for asking). I guess when we're young, these things help us define ourselves (albeit superficially) and help us put some order into our world. Although - I still have a list of my top 5 chip flavours, so I guess I haven't grown up that much yet...

One list that I'd have no chance of sorting into any order (and hopefully will never have to) is my favourite ramen places in Sydney. Right now, there are so many places doing amazing bowls of ramen, all with all different types of noodles, broths, meats and toppings, and there's not really one that's better than the other - they're just different. It'd be like picking your favourite kid, or favourite season of The Bachelor. Impossible.

Sydney's ramen culture is at an all high time right now, and the #NoRamenNoLife maxim has well and truly taken hold of our brains! Indeed, for some, ramen is more than just a delicious bowl of noodles - it's practically a religion (which is pretty believable when you consider that when you take the 'r' out of 'ramen', you're left with a fairly common end to a prayer). And with many places now offering the easier-to-digest, lighter-on-the-hips shio (salt) and shoyu (soy sauce) broths, as with as the richer, thicker tonkotsu (pork bone) broth, you can have ramen every day without feeling guilty!

As one of the relative newcomers to Sydney's ramen scene, Ramen O-San opened up in the Dixon House Food Court in Haymarket earlier this year. Owner and Chef Kazuteru Oh (hence the name O-San) has been in the ramen game for over 10 years, having opened his first ramen shop in his native Kyushu in 2004. Since then, he's won numerous awards, been featured in national Japanese media, has opened another 5 ramen shops in Japan (all in Tokyo), one in Phnom Penh, and now his first in Sydney. His expansion into Australia has been welcomed with open arms, with Ramen O-San being one of the CBD's most popular ramen joints and often selling out of everything before the end of the day!

A hardworking and humble man, Chef O-San tells me that he's enjoyed the process of adapting his recipes to suit both the Australian climate and our palates (and even now, he's continually refining things), and he finds that Australians tend to enjoy ramen that has stronger, more pronounced flavours. I'm certainly not complaining - the more flavour the better!

The menu at O-San is quite extensive, particularly given the size of the small kitchen behind the counter. Their ramen broths incude tonkotsu, creamy tonkotsu, 'sumo' (made with pork and chicken broth and served with pork kakuni/belly), black garlic tonkotsu, miso, 'collagen', spicy, and chicken shoyu; and then there are individual ramen accompaniments and rice bowls to choose from as well. As with all good ramen places, the broths are made fresh each day - each one spending between 8-10 hours on the stovetop to extract all of the flavour and goodness from the meat bones.

Lately, O-San has also been offering a limited number of serves of tsukemen each week. If, like me, you haven't had it before, tsukemen is a variation of ramen in which the noodles are served separately from the broth. More on this later.

With so many types of ramen to choose from at O-San, it's a bit of a first world problem trying to narrow it down! As can probably be predicted from my penchant for bone marrow, I'm really intrigued by the collagen soy ramen ($11.80), so it's first on the list. When it comes out, I'm surprised (and pleased) to see that there are actual pieces of collagen floating in the broth. I had assumed that the collagen would have just turned into gelatine and acted as a thickener for the broth, but it's nice to see that the collagen hasn't quite broken down.

Although the pieces of collagen are dispersed throughout the broth, you almost don't notice them as they're super soft (and with a different texture to fat) and quite mildly flavoured. Collagen aside, the broth is actually really clear, and I'm impressed with its delicious meaty and slightly smoky taste, which is helped along by the small cubes of wobbly pork belly hiding in the broth. The noodles here are the thinner variety, and they hold the broth well as you bring it all up to your mouth. Yum!

When you're amongst friends, no one cares how garlicky each other's breath is, so the equally-intriguing black garlic tonkotsu ramen ($10.80) also gets our attention. True to its name, the broth has a mysterious black colour to it, and it has a pronounced but not-overbearing garlic taste to it - similar to how roasted garlic turns into a sweet, creamy mash that you can virtually eat on its own.

As with the collagen ramen, this one has the thin style of noodles, accompanied by spring onion, sliced cha-shu, and cloud ear mushrooms for some crunch. It's a great variation on the original tonkotsu ramen, and it actually doesn't feel as thick as a regular tonkotsu broth, so it could be a lighter option for those who prefer (although maybe don't have it for lunch if you have client meetings in the afternoon!).

As I mentioned, O-San started serving tsukemen a couple of months ago (Chef O-San had been working on the perfect recipe for a few months before that, including for the handmade noodles), and they also offer a limited number of servings at Busshari in Potts Point on Sundays. Since the noodles and soup are served separately, the way to eat tsukemen is to grab a few strands of noodles at a time and dip them into the soup (not unlike dipping soba noodles into its accompanying broth). Given that the tsukemen available today, we're not going to miss our chance to have it (I freely admit to having FOMO!), so we go for the medium size ($16).

The tsukemen soup at O-San is made with a rich pork and seafood base, and Chef O-San gives us a chance to experience the separate flavours of the soup by serving it to us in three stages - firstly, just with the pork base, then with the seafood broth added to the same bowl, and lastly, once we're done with the noodles, topped with dashi broth so we can drink the rest of the soup.

The big bowl of tsukemen noodles are the thicker variety, and thanks to this thickness they have a lovely bounciness to them, similar to the 'al dente' concept with pasta. The noodles are served at just below room temperature, making this tsukemen a great option for a warmer day (just as Sydney's been experiencing lately - not long til summer!), and are served with a wedge of lemon to provide some refreshing acidity and help loosen the noodles if they start sticking together.

The plain pork broth is already quite flavoursome, with the cubes of pork belly once again adding some great extra flavour and texture. But after going back to the counter for the top-up of seafood broth (or it might just be a seafood oil), the flavour intensifies and changes quite markedly into a beautiful, complex soup. The seafood broth is made largely of prawn heads, which have now imparted their distinct flavour on the now-orange soup and provided a delicious, crustaceany 'hum' to the dish. Even though I'm getting pretty full by now, I can't seem to stop eating it all!

Finally, once the noodles are taken care of, the remaining soup is topped up with some hot dashi, making it perfect for drinking as a soup and providing a clean, light end to the meal.

It's hard to have a 'favourite' ramen place in Sydney, but O-San definitely makes of the list of 'one of my favourites'. Aside from the delicious and interesting ramen options they have, it's inspiring and heartening to see someone like Chef O-San care so much about his craft and go about it so humbly and diligently. No ramen, no life!

• Shop B1, Dixon House Food Court, 413-415 Sussex Street, Sydney CBD (Haymarket)

• https://www.facebook.com/osanramensydney

• Open Mon-Sun, 11:00-20:30 (although earlier if they run out!)

*I dined as a guest of Ramen O-San and SD Marketing Global (Washoku Lovers), but all opinions are my own.