Preheat the oven to 425 degrees . On a rimmed baking sheet, toss the carrots, onions and tomatoes with 3 tablespoons olive oil. Spread into a single layer, season with salt and pepper and roast, tossing halfway through, until golden, about 30 minutes. On a separate baking sheet, drizzle the bread cubes with 2 tablespoons olive oil, season with salt and pepper and toss. Bake until crisp, about 7 minutes.
Meanwhile, in a small bowl and using the back of a spoon, mash the garlic with a pinch salt. Whisk in the lemon juice, then slowly whisk in the remaining 1/3 cup olive oil; season with salt and pepper.
In a large bowl, combine the kale and roasted vegetables and toss with the dressing. Divide among 4 plates and top each with some croutons and a round of goat cheese.