For hard gainers and heavy bulking phases: this is a calorie-maximum meal, not an everyday plate. A deep pan of lasagna with 1.6 kg of beef, ricotta and whole-milk mozzarella. Cut it in four: each slab is a 2,400-calorie meal.
Preheat the oven to 190°C (375°F) with a rack in the centre. Use a deep 23 x 33 cm (9 x 13 inch) dish or a roasting pan.
Brown both beefs in a large pot over medium-high heat in two batches, breaking them up, until they reach 71°C (160°F), about 8 minutes per batch. Drain the fat.
Stir in the marinara and Italian seasoning and simmer over low heat for 10 minutes.
Mix the ricotta with the eggs, half the parmesan and the salt.
Layer a quarter of the meat sauce, then lasagna sheets, a third of the ricotta and a quarter of the mozzarella. Repeat twice, then finish with sheets, the last of the sauce, mozzarella and parmesan.
Cover with foil and bake 40 minutes, then uncover and bake 20 minutes more, until bubbling, browned and the pasta is tender when pierced.
Rest for 20 minutes so it holds together, then cut into 4 thick slabs.