Ever since tasting April Bloomfield's awesome fall green salads at The John Dory, that combination of crisp, bitter greens and savory anchovy dressing has been one of my favorite combinations.
Winter greens by their very nature are hearty in both texture and flavor. Radicchio, with its dark purple, frilly cabbage-like leaves are the bitterest of the lot, so I like to cut them with sweeter greens like Belgian Endive. The latter are grown completely underground to incur a process called etiolation, a natural occurrence in plants that grow in low-light conditions. In an effort to reach the light, rapid growth takes place, resulting in weaker cell structure, and no formation of chlorophyll. This is good for us when more tender leaves and a less bitter flavor are what we're after. Tight, pale yellow or pure white endives are what to look for.
Similarly, frisée (or curly endive) is sweetest at its core, where the sunlight has yet to reach, and the small leafy stems are still pale yellow and tender. For the best tasting frisée, you should discard the tougher dark green outer leaves (or safe them for soup), using just the pale green and yellow cores.
The anchovy dressing is a heavy-on-the-anchovy variation of a classic Caesar dressing. Mayo-based, with some lemon juice and Worcestershire sauce adding some acidity and bright depth.
With a few slivers of apples to add sweetness and some crunchy toasted walnuts, it becomes a simple salad that manages to hit you with enough levels of flavor and texture to eat like a full on meal.