Cut the spinach into 3cm pieces after removing the roots.

Rinse peeled shrimp and pat dry with paper towels.

Boil water in a pot, add salt, and cook spaghetti 1 minute less than package instructions. Drain.

Heat butter in a pan over medium heat, add spinach and sauté until softened. Add shrimp and cook until color changes.

Add flour to the pan and stir until no longer powdery. Gradually add milk, stirring over low heat until thickened. Season with salt and pepper.

Mix the cooked spaghetti into the sauce until well coated.