Step 1

Thinly slice 4 garlic cloves; halve remaining clove. Heat 2 tablespoons oil in a large pot over medium-high. Add shallots and thinly sliced garlic; cook, stirring occasionally, until shallots start to soften and garlic is golden, about 4 minutes. Add anchovies and 1¼ teaspoons salt; cook, stirring constantly, until anchovies have melted into shallot mixture, 1 to 2 minutes.

Step 2

Add wine and ¾ cup water to pot; bring to a boil over medium-high. Reduce heat to medium-low and add clams. Cover pot and simmer, shaking pot occasionally, until clams just open, 7 to 9 minutes. Remove from heat. Remove and discard any shells that did not open. Stir in parsley and lemon juice.

Step 3

Meanwhile, preheat broiler with rack about 8 inches from heat. Arrange bread on a baking sheet and drizzle both sides with remaining 1 tablespoon oil. Broil, watching carefully, flipping once, until golden brown on both sides, 1 to 2 minutes per side. Rub both sides of toasts with reserved halved garlic clove. Season with remaining ¼ teaspoon salt. Ladle clam mixture into bowls and serve with toasts.