Personally I feel 8 months is rather early for introducing snacks. Most routines I see or support on switch one of the day time milks to a snack somewhere closer to 10-11 months and then the other day milk to a snack at maybe 11-12 months 9still leaving 2 other milks at WU and BT).
I am also surprised that you were advised to introduce snacks so early because milk is higher in calories and all the nutrients LO needs at this age.
How long has it been between weigh-ins and has there been no weight gain? Could it be that rather than not gaining weight it is just that your LO is due a growth spurt so appears to have not done much growing but in a week or two could suddenly increase weight?
High fat (good fats) and proteins would be the focus. meat, fish, liver pate, fish paste, eggs, smooth nut butters.
There are lots of finger food ideas on this thread
Finger Foods (6 months+)I used to make a one egg omelet in one of those cute one egg frying pans. I cooked it a little whilst moving the egg around to make it fluffy then folded in half before it set so that the whole thing stuck together and ended up thicker which made it easy to slice into fingers for picking up. Eggs are basically safe in the UK as they all have the lion mark these days but I found cooking the omelet firm (fully cooked rather than lightly cooked like a regular one) made it much easier to slice and for LO to pick up.
Slow cooked meat is often a fav of younger LOs as it is so soft but can be picked up in big hunks easy to grip. Either stewed or use a slow cooker for example.
