Particles can get into a faucet and block the flow.
Disconnect the hot side at the valve under it.
Place a bucket under the valve going into the wall. Place your hand over the top (where water will squirt up) - to make the water go into the bucket. Then turn the valve on briefly to flush the line.
Next with the bucket under the disconnected hot water line, turn on the hot and cold on the kitchen faucet, then place your hand over the faucet spout. This will cause the cold water to go backwards out the hot water side and into the bucket - along with any particles which were clogging it.