Before You Begin
Prepare your cookware as needed. Cooking times and results may vary depending on your equipment and ingredients.
Prep
Preheat oven to 390°F (200°C). Soak sunflower seeds in hot water for 30 minutes, then drain.
Roast Vegetables
Place onion, pepper, tomatoes, carrots, and sweet potato in a baking dish. Drizzle with oil and season with salt, oregano, thyme, and chili flakes. Place garlic head cut-side down among vegetables.
Roast 35–40 minutes, until vegetables are fork-tender and edges are lightly caramelized.
Blend
Squeeze roasted garlic cloves out of skins into a blender. Add roasted vegetables, beans, sunflower seeds, basil, and broth. Blend carefully in batches if needed and avoid overfilling the blender when blending hot ingredients.
Simmer
Transfer the soup to a pot and simmer over medium heat for about 10 minutes, stirring occasionally, until it is heated through and slightly thickened. Taste and adjust seasoning as needed before serving.
Serve
Serve warm.