Salad of Fresh Herbs and Nasturtium Blossoms

1 small shallot, minced
2 tablespoons Champagne vinegar or fresh lemon juice
7 tablespoons (or more) extra-virgin olive oil, divided
3 cups mixed baby lettuce

1 cup (loosely packed) small fresh basil leaves
1 cup (loosely packed) baby spinach leaves
1 cup (loosely packed) fresh mint leaves
1/3 cup (loosely packed) 1-inch pieces fresh chives
1/3 cup (loosely packed) fresh chervil leaves

Nasturtium blossoms or other edible flowers (optional)

Whisk shallot and vinegar. Gradually whisk in 4 tablespoons oil. Season dressing with salt and pepper.

Combine herbs and greens in large bowl. Toss herbs and greens with dressing; season to taste with salt and pepper. Tuck nasturtium blossoms into the greens.

Note: dressing and salad can be made 2 hours ahead. Cover separately and chill.