To ensure that the lasagna doesn't come out watery, it's important that the greens go in dry. Let all the water evaporate during cooking, and then blot the leaves with a paper towel if necessary after removing them from the saute pan.
Adding toasted whole-wheat breadcrumbs gives this dish a nice crunch that balances out the creaminess of the sauce. Rather than baking the shells with the crumbs on top (which can make them soggy), toast the breadcrumbs separately, and toss a handful over each serving right before you put it on the table.
Detox Cred: Beets may take a while to roast, but their powerful healthy status makes it worth the wait. (For a tasty side dish, saute the green tops -- they have double the potassium, folic acid, and iron as the sweet roots.) Garlic and leeks, both health-boosting alliums, add delicious flavor and dimension to any soup.