In a medium bowl, whisk together the egg, yogurt, garlic, and ginger. Add the breadcrumbs, ground beef, ground pork, and season with 1 1/4 teaspoons salt and a dusting of black pepper. With lightly oiled hands, roll into heaping tablespoon-sized balls.
In a Dutch oven or large pot, heat the coconut oil over medium-high. Add the meatballs in a single layer and cook for 4 to 6 minutes, until browned on two sides but not fully cooked. Transfer the meatballs to a plate. Add a splash of chicken stock and scrape up any browned bits on the bottom of the pot.
Add the leeks and season with salt. Cook for 3 to 5 minutes, stirring occasionally, until golden brown. Stir in the tomato paste and cook for a minute or two more, until color deepens. Add the chickpeas and stir to coat with the leek mixture. Add the chicken stock, coconut milk, and bring to a boil. Season the broth with salt and pepper.
Cook the soup, covered, for 10 minutes, until flavors meld. Add the meatballs and simmer over medium for about 5 minutes, until just cooked through. Remove from the heat and stir in the spinach. Divide among bowls and garnish with jalapeño slices.