How to Make It
In a large skillet, heat the oil until shimmering. Add the fennel, cumin and caraway seeds and cook over high heat until fragrant, about 30 seconds. Add the onion, garlic and chopped chard stems and cook over high heat, stirring occasionally, until softened, about 6 minutes. Add the chard leaves, season with salt and pepper and cook over high heat until softened and any liquid has evaporated, about 8 minutes. Let cool, then fold in the goat cheese. Season with salt and pepper.
Preheat the oven to 375° and line a baking sheet with parchment paper. On a work surface, butter and stack the four sheets of phyllo dough; butter the top sheet. Spread the chard filling along a long edge, leaving about 1 inch of phyllo at each end. Roll up the phyllo to form a long cylinder, tucking in the ends as you go. Transfer the strudel to the baking sheet, seam side down and brush with butter. Bake for about 35 minutes, until golden and crisp. Let cool for 20 minutes, then cut into 12 pieces and serve.