1. Place greens and oil in a small stock pot or Dutch oven. Add enough water to cover; season with salt and pepper. Cover, set over medium heat and bring to a boil. Reduce heat to a simmer; let cook until greens begin to fall apart, about 1 hour. Drain greens and set aside.

2. Fill a medium saucepan with water and bring to a boil. Add corn; cook until tender, about 20 minutes. Remove corn and cut kernels from cob; discard cobs and set aside kernels.

3. In a large stock pot or Dutch oven, bring 10 cups water, celery, and celery seeds to a boil over medium heat; let cook for 30 minutes. Remove celery; set aside. Set pot of water aside.

4. In a medium saute pan, melt 3 tablespoons butter over medium heat. Add onions and celery; cook until browned, 8 to 10 minutes. Add to pot with celery seeds along with broccoli, carrots, cauliflower, corn, and greens.

5. Place pot over medium-high heat and bring to a boil, stirring to combine. Reduce heat to a simmer, and cook until broccoli turns a vibrant green color, 2 to 3 minutes. In a medium saute pan, melt 1/4 cup butter. Remove from heat. Gradually stir flour into melted butter until flour is dissolved and mixture has thickened; whisk into simmering vegetable mixture. Continue cooking, stirring occasionally, until thickened, 2 to 3 minutes more. Season with seasoned salt and pepper, whisk in 1 tablespoon butter, and set aside.

6. Preheat oven to 375 degrees. Line 2 baking sheets with parchment paper and set aside. Melt remaining 2 tablespoons butter; set aside. Lightly dust work surface with flour and roll out 1 piece of dough into a circle about 13 inches in diameter. Repeat process with remaining pieces of dough. Place 1 round of dough in a 9-inch deep-dish pie plate; fold overhanging dough inward. Ladle in half of the filling; cover with a second piece of dough and fold overhanging dough inward over the top of the cobbler. Score top in 4 or 5 places with a paring knife. Repeat process with remaining 2 pieces of dough and filling. Generously brush tops with remaining tablespoons of melted butter. Place each cobbler on a prepared baking sheet; bake until golden brown and bubbling, about 45 minutes.