This shouldn't be too hard, really, and for me I actually would far sooner have a 'clean' meal than a disgusting pre-made ready meal, even if it is from M&S... In fact, the smell of supposedly healthy pre-made meals being heated in the microwave is now a massive turn-off to me.
But this is because over time, my taste buds have been trained to appreciate the simpler things. I used to think 85% cocoa chocolate was too dark, but now if I have chocolate I can handle the 99%!
We think we have 'tastes' but in fact these are very changeable - did you used to only have coffee with sugar in it? It's pretty easy to wean yourself off it over a couple of weeks, isn't it?
The same goes for foods - many of my clients insist something is horrendous the first time they try, and while I will never force anyone to eat anything they don't like (that is a big part of how I get results with clients - ensuring the changes they make are ones they can see themselves adopting for life) I will always ask them to give it a few more tries before dismissing it out of hand. Sometimes it can just take a bit of getting used to, other times you'll just need to tweak things a little...
There is a great article from Leigh Peele, the 'Fat Loss Troubleshooter' about how you can actually systematically retrain (or 'reboot') your tastebuds if you find you are really struggling with adopting a cleaner style of eating. You can find the article HERE.