Soy sauce substitute

You can caramelise onions for making the rich sweet-savoury flavour, but you have to caramelise it slowly, and be very patient...it doesn't get made in 5 minutes.

Also, for something ready-made, Coconut Secret makes a coconut-based liquid aminos that contain no soy, and we got it at Whole Foods.

I'd do a reduction of PX dessert sherry, seasoned with salt and a mix of peppers (add more spices to taste). It's not exactly a replacement of soy sauce, but it has a dark, rich flavor as well.

Try some using sesame oil to go with that garlic and ginger idea.

For something requiring no preparation, my first choice would be Maggi Sauce, which is non-soy based. It has a bit more of a beefy flavor.

You can try Marmite or Vegemite. Both are made from yeast extract, dark colored, and very savory. They're also thick like molasses, so you can dilute with water to get an appropriate consistency.

Try Liquid Aminos.

For a teriyaki style sauce, I use Mama Sita's barbecue marinade sauce. http://www.msita.com/sauces.htm

The flavour is uncannily similar to teriyaki, especially after adding garlic, ginger and onion. The sauce also thickens quite nicely. I'm in a similar situation to your friend, so I've had to find some good alternatives.

The ingredients on the back of the bottle are: water, natural yeast extract, cane sugar, iodized salt, garlic, monosodium glutamate, caramel colour, black pepper, citric acid, disodium inosinate guanylate and 0.1% sodium benzoate (as preservative)

I'd normally stay away from a few of those ingredients, but this sauce is worth it if you have to be soy-free.

Bragg's Liquid Aminos contains soy [I had been looking into it for similar purposes]. I'd been thinking [before I found the coconut amino acids] about attempting to make a sauce by sauteing and pureeing mushrooms [with sesame oil, but not too much, as I find it can be too strongly dominant in a flavour profile of a dish if I'm not quite careful] and thinning it a bit with water. Another idea I'd kicked around was getting a dark smokey flavour from strongly [not time based (can get bitter), but adding more tea than usual] brewing smokey Lapsang Souchong and then reducing it into a thicker sauce.

I would suggest mushroom catsup. It is a thin, brown, salty and savory sauce that tends to be used much the same way as Worcestershire sauce - and similarly to soy sauce, to add salt and depth of flavor while cooking or to season at the table. It is one of my favorite vegetarian substitutions.

Geo Watkins' brand is safe for vegetarians and vegans, and (I just checked mine) does not contain any soy, not even soy lecithin which can be found in some unexpected places.

Alternatively, it can be made without too much difficulty, with common ingredients (the recipe I used is here).