Spanakopita Lasagna

Name: Spanakopita Lasagna
Ingredients: 2 teaspoons vegetable oil; 2 medium onions, chopped; 2 (10 ounce) packages frozen chopped spinach, thawed; 1 (15 ounce) container part-skim ricotta cheese; 3⁄4 cup skim milk; 1 (4 ounce) package feta cheese, crumbled; 2 eggs, lightly beaten; 3 cloves garlic, minced; 1⁄2 teaspoon salt; 1⁄2 teaspoon pepper; 1⁄4 teaspoon dried dill; 9 no-boil lasagna noodles; 8 ounces shredded part-skim mozzarella cheese; 4 plum tomatoes, sliced