Spinach lasagne

Name: Spinach lasagne
Prep time: 10 min
Cook time: 50 min
Total time: 1 h
Yield: 4 servings
Cuisine: Italian, European
Ingredients: ½ tsp of Black pepper; 200 gr of Frozen spinach; ¼ tsp of Ground nutmeg; 250 gr of Lasagne sheets; 50 gr of Parmigiano cheese; 40 gr of Plain flour; 100 gr of Ricotta cheese; 300 ml of Semi skimmed milk; 40 gr of Unsalted butter