Preheat oven to 400°F.

Over over medium-high heat, heat 1 tablespoon oil in a large frying pan. Add shallot and cook, stirring often, until softened, for 1 minute. Add garlic and cook stirring often, for 1 minute.

Add spinach in batches and cook, stirring, until wilted, 3 to 5 minutes.

Stir in dill, basil, parsley and nutmeg. Cook, stirring, for 1 minute. Season with salt and pepper.

Transfer spinach mixture to a large mixing bowl. Stir in ricotta and feta. (Use immediately or refrigerate for up to a day until ready to use).

Rub bell peppers with the remaining 1 tablespoon oil and sprinkle lightly with salt.

Place peppers in an 8-inch square baking dish. Divide the spinach mixture among the peppers and top each pepper with 1 tablespoon mozzarella.

Bake until the peppers are tender and cheese has melted, 30 to 35 minutes.

Serve immediately.