Stuffed peppers with zucchinis and Italian sausages

Ingredients

• 4 peppers of mixed colors, cut in half lengthwise and seeds removed
• Olive oil
• Salt and ground pepper
• 1 leek white part only, sliced
• 2 garlic cloves, finely chopped
• 2 cups white mushroom, finely chopped
• 2 cups zucchinis, finely chopped
• 1/2 teaspoon Italian spices
• Meat of 6 spicy Italian sausages
• 1/2 cup fresh parmesan cheese, grated
• 2 cups cheddar cheese, grated