A. Force Redirect to OPENDNS (without PI hole)
/ip dns
set allow-remote-requests=yes servers=208.67.222.222,208.67.220.220

/ip nat
add action=redirect chain=dstnat dst-port=53 in-interface-list=LAN protocol=tcp
add action=redirect chain=dstnat dst-port=53 in-interface-list=LAN protocol=udp

B. Force OPEN DNS (via PI hole)
/ip firewall nat
add chain=dstnat in-interface-list=LAN protocol=tcp dst-port=53 action=dst-nat to-addresses=10.0.0.31 to-ports=53
add chain=dstnat in-interface-list=LAN protocol=udp dst-port=53 action=dst-nat to-addresses=10.0.0.31 to-ports=53
add chain=srcnat src-address=10.0.0.0/24 dst-address=10.0.0.0/24 action=masquerade