Cannellini Bean Salad with Pesto

Preheat an outdoor grill to medium heat (350 to 375 degrees F (175 to 190 degrees C)). Brush bread slices generously with 2 tablespoons oil. Oil grill grates. Arrange bread slices, bell pepper, onion, zucchini, lemon, and garlic, cut sides down, on grill grate over direct heat; cover grill.

Grill bread, turning halfway through, until toasted, about 4 minutes. Grill lemon and garlic until cut sides are lightly charred, 4 to 6 minutes. Grill zucchini, bell pepper, and onion, turning halfway through, until tender and lightly charred, 5 to 6 minutes for zucchini and 8 to 10 minutes for pepper and onion.

When cool enough to handle, squeeze cloves from garlic halves. Rub a few garlic cloves over both sides of toast. Reserve about 3 cloves garlic for the pesto (save remaining garlic for another use). Cut or tear toast into bite-size pieces.

For pesto, pulse parsley, walnuts, Parmesan cheese, salt, reserved 3 cloves garlic, and juice of grilled lemon in a food processor or blender until chopped. With machine running, pour in remaining 1/2 cup oil in a thin stream until mixture is smooth.

Cut bell pepper, onion, and zucchini into bite-sized pieces; add to a large bowl, along with croutons, cannellini beans, and tomatoes. Toss to combine. Arrange salad on a serving platter. Drizzle with pesto; toss to coat before serving.