Bit of a shy guy around people sometimes;

you don't have to let silences drag out so long they become uncomfortable, because chances are he'd feel that to some degree as well,

wouldn't recommend filling in every blank space with some query about himself or anything, that can get frustrating for a person, but to be honest, the thing that's let me most open up around people when I was too shy is purely compassion, and others being open with me

be friendly through action, be willing to talk about yourself if he's not talking too much, small talk is cheap and shallow so don't go with the whole 'this food is nice isn't it' kind of attempt to break the shell, because that won't lead to a great discussion,

to be honest though, I know how it can feel frustrating on a date when conversation just doesn't seem to flow, I get like that even when talking with friends I haven't spoken to in a while sometimes, doesn't help when i'm on a date feeling a bit under pressure with someone completely new, but it seems to pick up naturally to a point where we're both just being open and things go from one subject to the next with a bit of time and patience, usually it starts with them talking about something they're passionate about or interested in, or just how their day has been, so long as there's content, an air of openness, and a vibe of friendliness; something to respond too, and something to inquire about without feeling as though i'm 'prying', with those elements I usually end up opening up and discussion ends up unfolding very naturally,

though I do put that same kind of effort in, from my perspective with some, probably unhealthy cynicism and shyness, it's such a relief when the other person seems comfortable just talking about /whatever/ in the first place, as opposed to trying to figure out what I can actually talk about with them, especially as I don't like talking about myself too much before I get comfortable simply conversing

basically, shoot the shit before you try to get close to them, if they see you're comfortable with just general banter, they'll start to open up more

sorry for the long winded explanation, but that's about all I can think of to help you out there