I have one of these fancy french baking books that says that the sourdough needs to be feed with a 2:1:3 ratio of water, starter and flour. But a lot of videos I see online basically just pour a little out, add equal parts of water and flour (seemingly regardless of how much starter they have) give it a mix and call it a day. What's the truth behind maintaining a sour? Not talking about storing in the fridge for now as the variation doesn't seem relevant to the question. Thanks for the advice! 
Use a microwave. Microwaves have been shown to preserve more nutritional value in vegetables than boiling in numerous studies. When it comes to maximizing the amount of nutrients retained in vegetables a microwave literally cannot be beat. A few studies have found that microwaving certain vegetables actually makes certain nutrients more available too so depending on the vegetable microwaving might actually be more nutritious than eating it raw.   If you don't want to use a microwave then you need to blanch them. I defrost mine on the counter, but if you're using enough water then you shouldn't need to worry about the temperature drop too much. Experiment and use common sense when adding frozen stuff to hot water.  Now, with the above out of the way, if you're eating enough vegetables it doesn't matter how you boil them when it comes to the micro-nutrients. The simple fact of the matter is that vegetables don't just contain nutrients, they're loaded, absolutely strapped, with them. If you actually eat enough vegetables - with a good amount of variety of course - you should really be getting all of the nutrients you need that you could get from eating vegetables regardless of the amount of nutrition lost to boiling. Cooking method isn't going to make a ton of difference, unless you boil them for 4 hours or something, but even with that if you just eat a few servings of vegetables that aren't cooked to death you should be fine. Keep in mind that adding a ton of fat or sugar to vegetables is going to affect your macro-nutrients(Macro-nutrients are protien, carbs, and fat, Micro-nutrients are vitamins and minerals and stuff)  One thing that's important to note is that you probably don't get all of the nutrients you actually need from vegetables. Most Americans don't get enough b12 so you should be taking b12 supplements.(The rate of b12 deficiency in omnivores is high enough to suggest that the average american isn't getting enough b12 from meat either so you should really be eating b12 fortified foods or taking supplements anyway.)  Before the argument starts, frozen vegetables lose less nutrients over time than "fresh" vegetables do. If you're not growing your own food, frozen vegetables are the most nutritional choice. 