Serve the salad with thinly sliced prosciutto and roll the greens inside each piece.
Preheat oven to 350 degrees. Toss pecans with 1 tablespoon oil, and season with salt. Spread on a rimmed baking sheet, and bake until fragrant and edges begin to darken, 10 to 12 minutes. Let cool, then coarsely chop.
Combine dandelion greens, dates, and half the Stilton in a bowl. Toss with lemon juice and remaining 2 tablespoons oil, and season with salt and pepper. Arrange salad on a platter. Sprinkle with pecans and remaining cheese. Serve with prosciutto.