I like to spend time in the kitchen and I love to make multi-course meals, especially this time of the year when it's getting cool and the kiddo is back in school. I have some favorite mains that take a bit of time, but I think if you have some time, having an appetizer, main, and dessert would be something different if you don't always get to sit down to a long meal (if the babe will let you sit down to a long meal

).
Like the pp said, Shepherd's Pie (or Cottage Pie if using ground beef) might take a bit of time depending on knife skills (I chop leeks, carrots, parsnip, celery, and garlic for mine, but I'm OK with a knife, so it doesn't take too, too long). When I grill a good steak, I like to take the time to make a delicious sauce (such as béarnaise) to go with it and that takes some time to make sure it doesn't break. Indian food usually takes me a bit of time to make (Mataar Paneer and Keema Mataar are two favorites). A roasted turkey is also time consuming. I make my marinara sauce in large batches and freeze, but when I make it, that takes a bit of time. On average, I spend about 2 hours per day in the kitchen and all of these things listed take me about that much time. Something else that takes a bit of time, believe it or not, are chicken quesadillas. Making the tortillas, quesadilla sauce, dry rub on the chicken, then grilled, cooled and sliced, sauteing seasoned onions and peppers, and making the guacamole... all before the quesadillas are assembled and cooked take some time.
Let us know what you end up making!