Place potatoes and parsnips into a large saucepan of cold water, cover and bring to the boil over high heat. Reduce heat and simmer for 12-15 minutes until vegetables are tender.
Drain and return to pan and toss over medium heat for a few seconds until dry. Remove from heat. Mash until almost smooth.
Using a wooden spoon, beat in oil then gradually beat in the hot milk until mash is smooth and season to taste and set aside.
Scoop avocado flesh into a bowl and add lemon juice and roughly mash and set aside.
Cooking the salmon and tomatoes
Heat a few tablespoons olive oil in large frying pan over medium heat. Cook tomatoes for 2-3 minutes until hot. Transfer to a plate and set aside.
Season salmon and place it flesh-side down into pan and cook for 2 minutes. Turn and cook for a further 2-3 minutes or until almost cooked through. Drain on paper towel.
Swirl avocado through the mash and drizzle with extra-virgin olive oil. Spoon the mash generously onto each serving plate. Place salmon across the mash and add tomatoes and lemon wedges.
Serving Size 4