1 Preheat oven to 325°F. Place beef, water, tomato paste, sugar, vinegar, chipotle pepper, cumin, salt and black pepper in stockpot.2 Cover and bake in 325°F oven 1-3/4 to 2-1/4 hours or until beef is fork-tender.3 Meanwhile cut squash lengthwise into quarters; remove seeds. Place squash cut side down in 13 x 9-inch glass baking dish, overlapping if necessary. 4 Add water. Bake in 325°F oven 1 to 1-1/4 hours or until fork-tender.5 Place each baked squash quarter onto serving plate. Fill with equal amounts of beef mixture. Top with tomato and avocado, if desired. Sprinkle with cilantro.