In a small bowl or measuring cup, combine oil, lemon juice, vinegar, maple syrup, and shallot. Season with salt and pepper. Whisk to emulsify.
Bring a large pot of salted water to a boil. Add fava beans and blanch for 2 minutes. Drain and shock in ice water. Remove outer skins and place beans in a large mixing bowl. Add baby greens, parsley, and mint.
Heat a grill pan set over high heat. Rub bread slices with garlic clove and brush or drizzle with olive oil on both sides. Grill until charred with grill lines, about 2 minutes per side. Set grilled bread onto a platter or individual plates.
Cut open avocado. Use a large spoon to scoop out flesh halves. Place on cutting board and slice lengthwise. Top each piece of bread with a few slices of avocado.
Whisk dressing to reincorporate. Drizzle over bowl of favas, greens, and herbs. Toss gently to combine. Divide salad among each piece of bread with avocado slices. Serve immediately. Yield: 4 appetizer servings.