Step 1: Peel and chop the parsnips and potatoes into small, uniform pieces. Place them in a saucepan, cover with cold water, and add a pinch of salt. Bring to a boil, then reduce heat and simmer for 8-10 minutes, or until very tender.

Step 2: While vegetables cook, pat the trout fillets dry with paper towels. Season both sides with salt and pepper. Heat half of the olive oil in a non-stick skillet over medium-high heat.

Step 3: Once the oil shimmers, carefully place the trout fillets skin-side down in the skillet. Cook for 3-4 minutes until the skin is crispy and golden. Flip and cook for another 2-3 minutes, or until the fish is cooked through and flakes easily.

Step 4: Drain the cooked parsnips and potatoes thoroughly. Return them to the hot saucepan. Add the milk and butter. Mash or blend until smooth, adding more milk if needed to reach desired consistency. Season with salt and pepper to taste.

Step 5: In a separate small pan, heat the remaining olive oil over medium heat. Add the spinach (or Swiss chard) and sauté for 1-2 minutes until wilted. Season with a pinch of salt.