Hi Rodrigo,
I'm in a similar position myself in that the saving aspect & comparatively low cost of living seem to be in hand. The big difference here in Ireland is the options for investing and getting respectable returns.
Vanguard do have operations in the uk but you need £100,000 to buy into a fund. For additional management fees you can buy their products through a platform like Nutmeg or Zen Assets, although you may need a uk bank account to become a client. Barclays will let you open a non-resident account if you keep a balance of £25,000. HSBC will if you have £60,000 with them between deposits and investments, and Monese will grant you one for £4.95 per month and a max balance of £40,000.
There are REITs and peer-to-peer lending operations based here, but I feel that they are a bit too new and novel in or market to justify the risk. Property seems to be bubbling again so I'm cautious on that front too. That said, some contributors on askaboutmoney.com have reported positive experiences in those areas, but they probably know more about this sorts of things than I do.
For stocks and shares there don't seem to be many passive funds available which means you either select a managed fund for extra fees and apparently less reliable returns, or pick your own basket of companies to buy into. Rabobank, DeGiro, and TD keep coming up on AAM as the tools for this approach. This is the next avenue I intend to explore but I've not got there yet.
Finally, you need to keep tabs on whether your shares will post dividends or reinvest in themselves as one will subject you to capital gains tax and the other to income tax, so the level of return broadcast on these forums just doesn't seem possible 'round our way. Also there are limitations on gain-loss offsetting to minimise tax liability, and there's a 'deemed disposal' every 8 years so they can charge CGT regularly too, regardless as to whether you actually sold those assets or not.
I'm still at the homework phase of this aspect (investment returns) myself. I've not used any of the services I mentioned above, just discovered that they exist. Realistically I'll probably throw my spare cash at the mortgage for a couple of years, decide if the pension is worth maxing out or not, and in the meantime learn which companies deserve my love and financing.
Hope this helps, would love to hear what you can also come up with.