Directions
Wash the greens extremely well by immersing them in cool water and agitate the water to remove any grit. Drain and repeat. Dry the greens well, then roll them, cigar style. Slice them crosswise into 1/4" chiffonades. Set aside.
Fillet the anchovies by brushing away any residual salt and press along the backbone with your thumb, turn it over and easily pull the backbone a ribs away. This step in unnecessary with canned fillets. Soak the fillets in cool water for 10 , then drain and set aside.
Heat a medium-sized skillet over medium high heat. Add oil, garlic, anchovies, and pepper flakes, if using. Cook, stirring, until fragrant with garlic, about 30 seconds.
Using a box grater held over the skillet, grate the tomato allowing all the pulp, seeds and juice to fall into the skillet. Add water and greens. Stir to combine, cover, and reduce heat to medium low. Cook, stirring occasionally, until greens are extremely tender and flavors meld, about 20 minutes.
Transfer the warm greens to a serving platter and top them with the grated parmesan cheese and (optionally) the poppy seeds.