Try the stinking carnivore pellets as suggested by
islandguy11. (Purposeful misspelling) or you can try soaking your pellet of choice in thawed bloodworm juice.
I second the hikari carnivore. Our delhezi will start looking for them as soon as they hit the water. Although, she gets a massivore pellet every once in a while now.
it's all about how fussy your bichir is. PB(B)s and endlicheri generally whack anything food related that touches the water. Lapradeis are a lot fussier - I've had one who went 3 months without eating anything and it still looks fat.
sometimes you gotta starve em if you're really serious about converting them to a pellet diet.
You can do 50/50 mix of pellets and tilapia or shrimp cut or chopped to the same size. They’ll associate the taste of the frozen food with pellets and gobble everything. Do you have separate tank for pellet training? Frontosas may steal food and spook bichirs.