While preheating your oven to 400°F, prep all your vegetables: cut the yellow squash and zucchini into 1/2-inch slices, halve the tomatoes, quarter the mushrooms, cube the eggplant into 1-inch pieces, and mince the garlic. In a small dry skillet over medium heat, toast the pine nuts for 2-3 minutes, stirring occasionally, until fragrant and lightly golden—this brings out their natural flavor and adds crucial texture to the finished dish. Set the toasted nuts aside.
Spread all prepped vegetables on a large sheet pan. In a small bowl, whisk together the olive oil, Italian seasoning, red pepper flakes, salt, and black pepper until well combined. Pour this seasoned oil over the vegetables and toss everything thoroughly with your hands or two spoons until every piece is evenly coated—this ensures even browning and flavor distribution during roasting.
Place the sheet pan in the preheated 400°F oven and roast for 25-30 minutes until the vegetables are golden brown and tender, with slightly caramelized edges. About halfway through roasting, give everything a stir and add the minced garlic from Step 1, which will infuse its flavor into the vegetables while they finish cooking—I do this timing adjustment to prevent the garlic from burning while still getting deeply caramelized.
While the vegetables roast, bring a large pot of salted water to a boil. Add the gnocchi and cook according to package directions (usually 2-3 minutes for fresh gnocchi) until they float to the surface and remain there for 1-2 minutes. Reserve about 1/2 cup of the cooking water, then drain the gnocchi gently in a colander.
Remove the roasted vegetables from the oven and drizzle with balsamic vinegar, stirring gently to distribute. Add the cooked gnocchi from Step 4 to the sheet pan with the roasted vegetables and toss everything together, adding a splash or two of the reserved gnocchi cooking water if needed to create a light, silky sauce that coats everything. This starch-rich water helps bind the dish together beautifully.
Divide the gnocchi and roasted vegetable mixture among serving bowls or plates. Top generously with freshly grated Parmesan and scatter the toasted pine nuts from Step 1 over each portion. Serve immediately while the gnocchi is still warm and the vegetables are at their best.