Cheesy Eggplant Rollatini

Ingredients (11)

• + kosher salt to taste add to pantry
• + 2 eggplants, cut lengthwise into 1/4-inch slices add to pantry
• ✓ 1 pinch ground black pepper
• + 4 cups fresh spinach add to pantry
• + ½ onion, chopped add to pantry
• ✓ 1 clove garlic, minced, or more to taste
• ✓ 1 teaspoon Italian seasoning, or to taste
• + 1 cup grated Parmigiano-Reggiano cheese add to pantry
• + ½ cup ricotta cheese add to pantry
• + 1 ½ cups marinara sauce add to pantry
• + 1 cup shredded mozzarella cheese add to pantry