Preheat oven as called for by your lasagna noodle or full recipe instructions, if baking.
Lightly oil the bottom of a 9x13-inch baking dish with a little extra-virgin olive oil.
Spoon a thin, even layer of tomato sauce across the bottom of the prepared dish.
Place a single layer of lasagna noodles over the sauce.
Spoon half of the ricotta cheese over the noodles and spread it evenly.
Distribute half of your desired fillings (for example roasted vegetables) over the ricotta.
Add more tomato sauce over the fillings to cover the layer.
Repeat: add another layer of noodles, then the remaining ricotta, the remaining fillings, and more sauce.
Top with a final layer of noodles, spread the remaining tomato sauce evenly over the top, and sprinkle with the shredded cheeses.
Bake according to the full lasagna recipe or noodle package directions until heated through and cheese is melted.