Sauté the Aromatics: In a large pot, warm the olive oil over medium heat. Add the finely diced onion, carrot, and celery. Cook gently, stirring occasionally, until the vegetables soften and the onion turns translucent, about 5-7 minutes.
Add Garlic and Spice: Stir in the minced garlic, chili flakes or Aleppo pepper, and chopped rosemary. Cook for another 1-2 minutes, allowing the garlic and herbs to release their fragrance without browning.
Combine Beans and Broth: Pour in the cooked navy beans and vegetable broth. Stir well to combine all ingredients. Bring the mixture to a gentle simmer, then reduce the heat to maintain a low simmer.
Blend to Creamy Perfection: Using a blender (immersion or countertop), puree the soup until smooth and creamy, leaving a little texture if preferred. Be cautious when blending hot liquids to avoid splattering.
Incorporate Greens and Season: Return the blended soup to the pot if using a countertop blender. Stir in the chopped kale and simmer gently for 5 minutes, allowing the greens to soften without losing their vibrant color. Add lemon juice, salt, and pepper to taste. Adjust seasoning as needed.
Finish with Fresh Herbs: Remove the soup from heat and stir in the chopped parsley for a fresh herbal lift. Serve hot, optionally drizzled with lemon-infused olive oil or your favorite finishing touch.