Melt butter in a large pot over medium heat.
Add garlic and celery. Cook for about 5 minutes, stirring occasionally. Add clam juice, cream, cream cheese, sage, lemon juice and lemon zest. Let it simmer for about 10 minutes without lid.
Add the fish and shrimp. Simmer for 3 minutes or until fish is just cooked (should flake easily). Add the baby spinach and stir until wilted.
Season with salt and pepper to taste.
Garnish with fresh red chili and fresh sage before serving for extra flavor and splash of color.