Spinach and Ricotta Lasagna with Tomato Sauce
Filling - Wilt spinach in hot pan with splash of water (1-2 min). Drain, squeeze dry, chop. Mix with ricotta, egg, 200 g / 1¾ cups mozzarella, 25 g / ¼ cup Parmesan, nutmeg, red pepper flakes, salt, pepper.
Sauce - Use tomato-basil sauce as-is (warm with torn basil if you like).
Assemble (23x33 cm / 9x13 inch dish) • Thin layer sauce on bottom • Lasagna sheets • ⅓ spinach filling • ⅓ remaining sauce Repeat 2 more times. Top with final sheets + last sauce + remaining 250 g | 2¼ cups mozzarella + 25 g / ¼ cup Parmesan.
Bake - 205 °C / 400 °F, center rack. Cover with parchment + domed foil → 20 min. Uncover → 10 min until golden and bubbly.
Rest 5-10 min before cutting.
Make-ahead: Assemble up to 24 h ahead, fridge. Add 5-10 min to covered bake if cold.