I get asked this a lot, usually by someone who has just paid for a bowl in a restaurant and wants to know how far they can get in their own kitchen. The answer is: all the way, if you are honest about what it takes. Here is the list, what each part costs you in time, and where you can cut corners without ruining the bowl.

The six things in a real bowl
Broth. The foundation. A rich pork broth is a day at a rolling boil; a clear chicken broth is most of an afternoon at a gentle simmer. There is no version of either that takes half an hour.
Tare. The seasoning, made separately from the broth and added to the bowl. Salt, soy or miso based. An hour of work, then it rests, and a batch lasts weeks in the fridge.
Aroma oil. Fat with something infused in it: garlic, spring onion, chilli, smoked fat. Twenty minutes, and it is the difference between a bowl that smells of ramen and one that smells of soup.
Noodles. Fresh, alkaline wheat noodles. Making your own is a craft in itself and I would not start there. Buy them fresh if you can find a maker; dried ramen noodles are a fair second, instant ones are not.
A protein. Chashu is the classic, pork belly rolled and braised low and slow, then chilled overnight so it slices. That is the second day. Chicken or tofu take less time but still want a marinade and a rest.
Garnishes. Spring onion, bamboo shoots, wood ear mushroom, a marinated egg. The egg alone is a soft boil, a peel and a night in soy. Small things, but they are what make the bowl look like the picture.
The from-scratch route
Two days. Day one is the broth, the tare, the oil and getting the chashu into the braise. Day two is slicing, marinating eggs, cooking noodles and building bowls. It is a wonderful weekend if you love this stuff, and I would encourage anyone to do it once, because you will never look at a bowl the same way again. It is not a Tuesday.
What you can skip
You can skip making noodles. You can skip the egg if you must, though I would rather you didn't. You can make a smaller, shorter broth and accept a thinner bowl. What you cannot skip is time on the broth and a proper tare, because those two are the ramen. Everything else is decoration.
The shorter route
Or you let someone else do the two days. That is what we are for. Our kits have the broth cooked and seasoned, the aroma oil made, the chashu braised, the noodles fresh and the garnishes portioned, so what is left is 10 minutes and a pan of boiling water.
The three signature bowls and this season's special are here. Order by Sunday 8pm. Delivered Thursday or Friday.