Preheat your oven to 350°F (175°C).
Cook pasta according to package instructions until al dente, drain, and set aside.
In a large skillet, sauté garlic in a small amount of olive oil over medium heat until fragrant.
Add spinach to the skillet and cook until wilted, then remove from heat.
In a large mixing bowl, combine cooked pasta, shrimp, fish, wilted spinach, heavy cream, lemon juice, salt, and pepper.
Transfer the mixture to a greased baking dish and sprinkle with cheddar cheese and breadcrumbs.
Bake in the preheated oven for 25-30 minutes, or until the top is golden and bubbling.
Remove from the oven and let it sit for 5-10 minutes before serving.