Add the diced onion to the crock pot.
Place the chicken on top and add the frozen vegetables.
Sprinkle with flour and seasonings.
Cook on low for 6 hours.
Two hours before serving (after 4 hours cooking time), roll out each biscuit and cut each one into 6 pieces. Place the cut up biscuits on top.
When the biscuits are finished cooking, remove the chicken from the crock pot and shred and then return to the crock pot.