Preheat oven to 350. Melt butter in heavy large skillet over medium-high heat. Add onions, celery, both bell peppers and garlic; sautÃ© until tender, about 5 minutes. Add Worcestershire sauce, hot sauce, cumin, salt, cayenne, black pepper and nutmeg; stir until fragrant, about 1 minute. Add ketchup, half and half and bay leaves; simmer 5 minutes. Cool completely. Discard bay leaves.
Using hands, mix beef, pork and eggs in large bowl. Add vegetable mixture and mix until well blended. Transfer mixture to 9x5x3-inch loaf pan, pressing to fit.
Bake until meat loaf is golden brown, feels firm to touch and thermometer registers 160 when inserted into center, about 1 hour 30 minutes. Transfer pan to rack and cool slightly.
Try substituting olive oil for the butter, and FF evaporated milk for the half-and-half.