Creamy tuna potato carrot pea casserole

Preheat oven to 220 Celsius. Scrub and halve the potatoes, and boil them in salted water (peel after they boil as it's easier). Immediately peel and slice the carrots into 1/2 inch thick discs, and add to the boiling potatoes. In a frying pan with the olive oil, fry the chopped onion, cauliflower, chile, garlic, and salt and pepper until browned, about 20 min (watch it while you're boiling and peeling the potatoes). When the potatoes are about done, peel them, turn off the boiling water and add the frozen peas to the same pot along with the carrots (the peas will thaw while you peel the potatoes). Just before you reserve the 3 cups of broth, mix the peas and carrots with the garlic, onion, cauliflower and chile sauté. Make the cream sauce: over medium heat, add the flour and butter to the reserved potato/carrot broth and stir constantly until clumps disappear. Add milk, yogurt, cumin, nutmeg, salt and pepper to the flour butter broth, stir until smooth and add chunks of cheddar, stirring until melted and smooth. Finally, layer the ingredients in a large casserole dish or deep baking pan: bread crumbs at the bottom; potato cubes; tuna fish; 1/2 white sauce; cauliflower, pea, carrot, onion, etc. sauté; 1/2 white sauce; bread crumbs to garnish (optional). Bake uncovered for 30 min at 220 Celsius, until browned. Let cool for ten minutes before serving.