Preheat the oven to 350F. Line a large baking sheet with parchment paper and set aside.

In a microwave safe bowl, add your cream cheese, mozzarella cheese, and parmesan cheese, and microwave in 30 second spurts, until the cheese has mostly melted. Add the eggs and whisk together, until a smooth batter remains.

Transfer the batter onto the lined sheet and bake for 15 minutes, until the edges are firm. Remove at let cool.

In a non-stick pan, add some oil on medium heat. Once hot, add the onions and garlic and sauté for 5 minutes. Add the ground beef and mix for 3 minutes, before adding the marinara sauce. Continue cooking for a further 5 minutes. Remove from the heat.

Start assembling the lasagna. In an 8 x 8-inch pan, cover it completely with tin foil. Slice the keto lasagna sheets into 6 even pieces. Place two pieces on the bottom of the pan, followed by a 1/2 cup ricotta cheese, a third of the sauce, and a 1/2 cup of the mozzarella cheese. Repeat the process until the entire lasagna is assembled.

Place the assembled into the oven and bake for 30-35 minutes, or until the tops are golden brown and the sauce is bubbling. Remove from the oven and let cool for 5 minutes, before serving.