The result sees Forest reach the round of 16 play-offs.
Igor Jesus continued his scoring spree with a brace on the night and Dyche said afterwards: "It has not been easy through various games, the schedule, planning, travelling and all that sort of stuff.
“To come out of a disappointing one in Braga and then to deliver that I am very pleased. I said last time I want them to lay a marker down and put constant doubt in my mind. It has been very difficult, but I am really pleased and I am pleased for the supporters as well to enjoy that.
"Pleased with him (James McAtee) we have been speaking to him trying to play with freedom. I thought Dan Ndoye was super sharp tonight. Some of the games hasn't been where he (McAtee) wants to be or where we want him to be. Tonight, he was and I am pleased for him. He has been putting the work in without a doubt.
"In all these games, particularly the Premier League, if your framework is not good you can get opened up, but it is equally coming off that to play with freedom. There has been good signs recently and good signs tonight."
Priorities
Dyche says Premier League survival remains the priority, though Forest also want to do well in Europe.
He added: "I was really pleased with that tonight. There was that authority being a good Premier League outfit, a good squad of players and delivering a proper performance.
"Look, the Premier League is the bread and butter. The club I saw this club for years and years try get back in the Premier League, so they did. Last season was a superb season which got us into this competition. I think we made it clear we want to do well in it.
"We take this competition serious, but we have to remember the Premier League, the club worked for years and years to get back there. It is finding the balance. We want to make a winning mentality."