Grilled Potato Squash with Marjoram

Ingredients

• 3 tablespoons fresh lemon juice
• 2 tablespoons minced shallot
• 1 tablespoon plus 2 teaspoons chopped fresh marjoram
• 1 teaspoon finely grated lemon peel
• 1/4 cup plus 3 tablespoons extra-virgin olive oil
• 1/2 pound small fingerling potatoes (such as Russian Banana), unpeeled, halved lengthwise
• 1 pound assorted summer squash (such as zucchini and yellow crookneck), cut on diagonal into 1/3-inch-thick slices
• 1 large red bell pepper, cut into 1-inch-wide strips