Place beans, 3 cloves of garlic, water, and sage leaves in the crockpot; cover and cook on HIGH for 4 hours until beans are soft. Do not add salt at this stage.

Meanwhile, preheat oven to 400°F. Place remaining garlic cloves in the center of aluminum foil, cover with olive oil and a pinch of salt, then seal tightly and roast in the oven for 25-30 minutes until soft and golden.

Remove roasted garlic from oven and set aside until beans are cooked. When beans are soft, add bouillon and stir until dissolved. Transfer some beans, liquid, and roasted garlic to a blender and blend until smooth.

Pour blended mixture back into the crockpot. Repeat blending remaining beans and garlic until desired creamy texture is achieved. Use an immersion blender if available for convenience.

Taste and adjust salt and pepper as needed. Serve hot, garnished with fresh sage leaves and whole roasted garlic cloves if desired.