Zucchini rice and cheese gratin

If you're a fan of cheesy gratins and want to incorporate some fresh zucchini into your meal, this Zucchini Rice and Cheese Gratin is a perfect choice. It's a comforting and savory dish that combines the mild flavor of zucchini with the creamy goodness of cheese and rice.

Ingredients:

• Butter for dish
• 2 1/2 pounds (about 1 1/8 kg) zucchini
• 2 1/2 teaspoons kosher salt (I use Diamond brand, use 1 1/2 of other brands)
• 1/2 cup (90 grams) plain, uncooked white rice
• 1 medium onion, minced (about 1 cup)
• 5 tablespoons (75 ml) olive oil, divided
• 2 large cloves garlic, mashed or finely minced
• 2 tablespoons (15 grams) all-purpose flour (optional)
• 1/2 cup milk, as needed, although water or broth of your choice would work just fine [1/2 cup needed for streamlined directions, less for original]
• 2/3 cup (55 grams) grated Parmesan cheese, divided
• Salt and pepper