Make-it-don't-buy-it Frozen Vegetarian Burritos

INGREDIENTS

• 5 ounces baby spinach (about 8 loose cups)
• Nonstick cooking spray, for spraying burritos (if reheating in the oven)
• 10 ounces frozen butternut squash chunks (not thawed)
• Kosher salt
• 1 cup brown rice
• 1 tablespoon tomato paste
• 1 teaspoon ground cumin
• 1 cup reduced-fat shredded Cheddar
• One 15-ounce can black beans, drained and rinsed
• Six 10-inch whole wheat flour tortillas or wraps
• 1 small onion, chopped
• Hot sauce
• Serving suggestions: reduced-fat sour cream, salsa and guacamole, optional
• 1 tablespoon olive oil
• 2 teaspoons chile powder