My experience with catching lgb is using minnows off the hook. I use a bopper depending on the depth it works most of the time however its a pond, probably would work in that condition. Also If you have seen it twice you might have a good idea where it lurks so its gonna be better for you. Worms also work too but I do have a better success with minnows vs worms when it comes to largemouths.
P.S. if youre not squeamish, go ahead and try to hand net in some smaller fish from that pond such as baby blue gills, my biggest fish from bass to catfish have been from that same location that I have fished in. 3-4 inches at the most. (used buffalo, drums, white bass, red sunfish, bluegills, crappies, local minnows and so on) then use em as bait. Thats where I catch the huge fish- from channel catfish to blue catfish using that method- however I do not fish for largemouths as I used to.