Preheat oven to 375°. Cut squash in half lengthwise; discard seeds and membrane.
Place squash halves, cut sides down, on a baking sheet; bake at 375° for 45 minutes or until tender.
Cool. Scoop out pulp from shell. Set aside 2 cups pulp, reserving remaining pulp for another use.
Combine squash pulp, milk, and next 4 ingredients (milk through egg white) in a food processor; process until smooth.
Pour into 1-quart souffle dish coated with cooking spray. Place souffle dishes in a 9-inch square baking pan; add hot water to pan to a depth of 1 inch.
Bake at 375° for 40 minutes or until puffy and set.
While squash is baking, heat oil in a deep saute pan or dutch oven.
Add garlic cook for 1 minute, add greens cook 2-3 minutes more.
Add 2 cups water and 1/2 teaspoon salt and let simmer for 10 minutes.