Step 1

Remove the thick inner stem from the cauliflower, slice into thick 1-inch slabs.

Step 2

Preheat a cast-iron grill pan over high heat.

Step 3

Rub the cauliflower with olive oil and arrange the pieces in a single layer in the preheated pan.

Step 4

Grill the cauliflower until charred on the outside and crisp-tender inside, about 4 to 5 minutes, flipping halfway through.

Step 5

Transfer the cauliflower to a cutting board, chop into bite-size pieces, and place in a large mixing bowl.

Step 6

Peel and dice the potato into 1⁄2-inch pieces, transfer to a large saucepan, cover with 4 inches of cold water, and bring to a rolling boil over high heat. Reduce the heat to medium and cook the potatoes for 6 to 8 minutes, or until almost tender.

Step 7

Stir in the peas and cook another minute. Reserve 1⁄4 cup of cooking water, then drain the potatoes and peas and rinse with cold water. Add these vegetables to the cauliflower.

Step 8

In a food processor, pulse together the pesto ingredients plus 2 tablespoons of the potato cooking water until smooth. Spoon onto the vegetables, add the nuts, and combine thoroughly.

Step 9

Cover and chill for 10 minutes to blend flavors. Serve the salad slightly chilled or at room temperature. Garnish each serving with a few nuts.