-
1
Rinse anchovies briefly and chop.
-
2
Heat 2 tablespoons of olive oil over low heat in a small skillet and add anchovies and garlic.
-
3
Stir until garlic is fragrant and just beginning to color and anchovies have broken down into smaller bits.
-
4
Transfer to a mortar and pestle.
-
5
Use pestle to grind mixture into a paste.
-
6
Add lemon juice or vinegar to the still-hot pan and stir to deglaze bottom of pan, then transfer to mortar and pestle.
-
7
Add mustard.
-
8
Work together, then slowly add 3 tablespoons of olive oil and walnut oil, one tablespoon at a time, working each tablespoon into anchovy mixture before adding next.
-
9
Work in walnuts and mash with the pestle until the sauce is thick.
-
10
Season to taste with freshly ground pepper (the anchovies should provide enough salt).
-
11
Heat a heavy cast iron pan over medium heat or prepare a medium-hot grill.
-
12
Cut radicchio into wedges about 1 1/2 to 2 inches thick at the widest point.
-
13
Place in a bowl and toss with remaining olive oil.
-
14
It should be lightly coated all over.
-
15
Season with salt and pepper.
-
16
Grill, turning often, until lightly colored, charred in places and soft, about 8 to 10 minutes (do this in batches if using a pan).
-
17
Arrange radicchio on plates or on a platter.
-
18
Either drizzle the sauce over the radicchio or serve it in ramekins with each serving.
-
19
Serve radicchio hot or at room temperature.
