Marina, to our taste it didn’t taste too sweet. However it does have both Maple syrup and Sweet Chilli sauce does contain sugar. The idea behind the Flavour Bombs is to tweet the recipe to your needs. In this case you could replace the Sweet Chilli sauce with just Chilli sauce. Or you could use onion , ginger and garlic to give it kick.
If DH is likely to still find this too sweet you could make a Bomb with Canned diced Tomato, soy , onion, garlic and olives and capers. I would freeze this in Plastic Zip lock bags. How ever even with this, for our taste I would add something sweet to balance the acid in the tomatoes.