The phrase "and watched with a" is correct and usable in written English.
It can be used when describing an action of observing something with a particular emotion or state of being.
Example: "She sat by the window and watched with a sense of wonder as the fireworks lit up the night sky."
Alternatives: "and observed with a" or "and looked on with a".
Black held steady, kept the ball deep to Lottner and watched with a slight smile as the German's two final backhands sailed into the net and wide.
After a trio of Dutch tourists pounded on the front gate and refused to retreat, Mr. Tashi's 45-year-old nephew stepped outside and watched with a mixture of curiosity and annoyance.
Inside, Dr. Tarter plopped down in front of a computer and watched with a suspicious eye as the display popped with a row of numbers indicating that a narrow-band signal — the signature of an artificial source — had been detected.
Rolf Stagg huddled near the city's waterfront on a recent morning, rolled some loose tobacco inside a torn scrap of newspaper and watched with a mix of derision and curiosity as a massive football fan village rose before his eyes.
I sat and watched with a heavy heart as she stole sanitary products from the supermarket, remembering going without, or folding up a clean sock, or balling up toilet tissue on the heaviest days.
And so it was with the greatest pleasure and no regret that Philip flung the boy off the roof, and watched with a sense of mounting satisfaction as his body flailed uselessly in the air for a few fleeting seconds before hitting the tarmac with a dull thud.
After making the post, I sat back and watched with an increasingly open mouth as more and more people commented on the statement.
If you sit and watch with a bunch of English fans you see it all the time.
"[Writer] Tony Briggs really wanted it to be a story that anyone could sit down and watch with a smile on their face".
Most readers have been in the position of being stopped for speeding and watching with a faint heart as the police officer wrote out a ticket.
In the row behind the Fanatics, an Australian tennis coach listened and watched with amusement and made a prediction.
