In a large skillet, saute onion in olive oil until tender. Add garlic; cook 1 minute longer. Stir in spinach. Cook about 5 minutes or until all the water has evaporated and the spinach starts to stick to the pan, stirring constantly,. Transfer to a large bowl.
In the same skillet, brown meat; drain and add to spinach mixture. Stir in the cheese, cream, eggs, oregano, salt and pepper; mix well. Set aside.
Cook lasagna noodles according to package directions; drain. Cut each noodle in half widthwise; spread out noodles side by side on a large piece of foil. Place 1 heaping tablespoon of filling at one end of noodle; roll up. Repeat with remaining noodles and filling.
Pour about 1 cup of tomato sauce in the bottom of a 13x9-in. baking dish. Place two rolls, seam side down, vertically on both sides of the baking dish. Place remaining rolls in four rows of three rolls each; set aside.
For cream sauce, melt butter in a heavy saucepan over medium heat; stir in flour until smooth; gradually add milk and cream. Bring to a boil, cook and stir for 1 minute or until thickened. Remove from heat; season with salt and pepper. Spread cream sauce over lasagna rolls. Cover with remaining tomato sauce. Sprinkle with cheese.
Bake at 375°, uncovered, for 20-30 minutes or until hot and bubbly.