I started by combining the ricotta, grated parmesan, eggs, salt, and pepper in a bowl. Stirring it all together until smooth created the perfect creamy filling. This step might seem simple, but it sets the tone for every cheesy bite ahead.
In a large saucepan, I melted butter and sautéed garlic until fragrant. I slowly whisked in the flour to make a roux, then gradually added the milk and heavy cream. As the sauce thickened, I stirred in mozzarella, fresh spinach, and chopped basil. It became creamy, green-flecked, and full of flavor.
With the oven preheated to 350°F, I greased my 9x13 baking dish and spooned in a layer of white sauce. Then came the oven-ready noodles, a generous scoop of ricotta mixture, shredded chicken, and more sauce. I repeated the layers, finishing with extra mozzarella and the halved cherry tomatoes right on top.
I baked the lasagna uncovered for 45 minutes, watching for the cheese to bubble and brown. Toward the end, I broiled it for a few minutes to get a golden, crisp top. The kitchen smelled incredible at this point!
After baking, I let the lasagna cool for about 15 minutes. This helped the layers set, making it easier to slice. Finally, I drizzled balsamic glaze on top and scattered fresh basil leaves for that picture-perfect finish.