Heat 1 tablespoon oil in a small non-stick skillet over medium heat. Add garlic and cook, stirring, until just beginning to brown, 1 to 2 minutes. Remove from the heat.
Coarsely chop half the cucumber and half the avocado and place in a food processor. Add tomatillos, bell pepper, jalapeno to taste, and the garlic. Process until smooth. Transfer to a large bowl. Stir in broth, sugar, and salt.
Dice the remaining cucumber and avocado and place in a medium bowl. Add olives and scallions. Drizzle with the remaining 1 tablespoon olive oil and gently toss to combine.
Ladle the gazpacho into bowls and top each portion with about 1/4 cup salad.