Preheat the oven to 400°F (200°C).
In a large bowl, toss the baby potatoes, red bell pepper, and zucchini with 1 tablespoon olive oil, 1/4 teaspoon salt, and 1/4 teaspoon black pepper until evenly coated.
Spread the vegetables in a single layer on a large baking sheet.
Place the baking sheet in the oven and roast the vegetables for 10 minutes.
Meanwhile, in a small bowl, combine 2 tablespoons olive oil, minced garlic, dried dill, dried parsley, 1/2 teaspoon salt, and 1/4 teaspoon black pepper.
Remove the baking sheet from the oven and push the vegetables to the sides to make space in the center.
Place the salmon fillets skin-side down in the center of the baking sheet.
Brush the salmon fillets evenly with the olive oil and herb mixture.
Top each salmon fillet with 2 lemon slices.
Return the baking sheet to the oven and bake for an additional 10 minutes, or until the salmon is cooked through and flakes easily with a fork.
Remove from the oven and let rest for 2 minutes before serving.