If you want to make this for picky eaters, use an immersion blender to make the veggies disappear into the pasta sauce.
Choose a high quality pasta sauce that you love. That is where all of the seasoning comes from. I love Bertolli's(R) Arrabiatta and I add 3 cloves of minced garlic to the veggies. Although extra sauce seems inconvenient, 1 jar does not create a moist enough lasagna. We always have leftovers, so I top the cold lasagna with leftover pasta sauce and microwave. This keeps it from becoming dry when reheated.