Preheat oven to 350 degrees.
Lay the salmon fillets, skin sides down, on a baking sheet and pat dry with a paper towel.
Place the butternut-squash pieces and cherry tomatoes around the salmon. Drizzle olive oil over the salmon and vegetables.
Sprinkle salt and pepper over salmon and vegetables, then lay lemon slices over the top and bake for 30 minutes. Turn off the heat and leave the pan in the oven for 5 minutes before serving.