1. Preheat the oven to 400 degrees.
2. Add the tomatoes to a rimmed baking sheet or dish and add in 1 tablespoon of the olive oil, the salt and red pepper. Toss to combine.
3. Bake for about 20 to 25 minutes, stirring once halfway through, until some of the tomatoes have burst and released some of their juices. Set aside. Meanwhile, bring a pot of lightly salted water to a boil.
4. Add in the soba noodles and cook until al dente (according to the package directions).
5. Drain and then rinse well with cold water. Meanwhile, set a large skillet over medium heat.
6. Add in the remaining 1 tablespoon olive oil. When hot, add in the red onion and cook for about 2 to 3 minutes, until it starts to soften.
7. Add in the mushrooms and cook for about 5 to 7 minutes, until tender.
8. Add in the spinach leaves and cook until wilted, about 1 to 2 minutes. Turn off the heat and add in the tomatoes and soba noodles. Toss until well combined. If the noodles seem a little dry, drizzle in another 1 to 2 teaspoons of olive oil. Taste and season with salt and additional red pepper flakes to taste.Scoop some of the pasta mixture into a serving bowl. Top with some of the walnuts, goat cheese and hard-boiled eggs.