Pre heat oven to 180 degree C.
Place diced potato and sweet potato on a lined tray, drizzle with olive, sea salt and minced garlic and mix to combine/ coat.
Pop into pre heated oven and allow to cook for 10-15 mins (larger pieces of potato/ sweet potato will take a little linger to cook). You want the potatoes to start to feel soft to touch. Remove from oven.
Add the salmon fillets to the baking tray with the potatoes, sprinkle with salt & pepper, and drizzle with lemon juice.
Put tray back into the oven for a further 10-15 mins (depends on how you like your salmon cooked).
Remove from oven once cooked (to your liking).
Serve salmon with roasted potatoes, and a non-starchy green salad.