Spinach and Ricotta Lasagna - SavvyMom

Ingredients

• 3 cups ricotta cheese
• 2 eggs, lightly beaten
• 1 cup grated mozzarella
• 1 tsp kosher salt
• ½ tsp black pepper
• 2 Tbsp unsalted butter
• 1 Tbsp olive oil
• ½ medium onion, finely chopped
• 1 clove garlic, minced
• 2 (10 oz) packages frozen chopped spinach, drained off any excess water
• ¾ cup unsalted butter
• ½ cup all-purpose flour
• 4 cups milk, warmed
• 1 heaping Tbsp Dijon mustard
• ¼ tsp fresh grated nutmeg
• Kosher salt and pepper
• 3/4 lb oven-ready lasagna sheets
• 1 cup grated Parmesan cheese