Wash spinach leaves. Blanch by dipping leaves into boiling water for one minute, then plunging them into a large bowl of cold water. In a food processor, coarsely puree the spinach, adding jalapeños if you prefer spice. Set aside.
Heat oil in a wok. Add onions, bay leaves, cinnamon stick, and cardamom pods; fry until onions are translucent, about 10 minutes. Add garlic and fry for 2 minutes longer.
Add tomatoes, turmeric, red chili powder and yogurt and cook 10 minutes Add salt to taste. Add the spinach paste and paneer and cook over low heat for about 5 minutes.
TO GARNISH: Heat butter in a small saucepot and add ginger. Stir until fragrant, then remove from heat and add cream. Garnish Palak Paneer with ginger mixture. Serve hot.
Serve with roti, naan, or steamed basmati rice.