Mix 2 Tbsp. (30 mL) olive oil, garlic, salt, and pepper in a low-rimmed dish. Toss in the shrimp to marinate while preparing the vegetables. Pull the leaves off the bottom three-quarters of the rosemary branches and soak them in cool water for 10 minutes. Pat dry. Boil beans in slightly salted water until just cooked; about 7 to 10 minutes. Plunge into cold water to stop cooking and retain colour; drain. On a flat serving dish or on individual plates, layer with arugula and beans, followed by cucumber and tomatoes.
Thread three shrimp on each rosemary branch. Grill on a barbecue or in a grill pan for about 2½ minutes per side. Squeeze with lemon juice after turning.
While the shrimp are cooking, use a teaspoon to scoop out pieces of avocado and place on top of the tomatoes.
Drizzle the vegetables with balsamic vinegar and a robust olive oil. Sprinkle with salt and pepper, top with the shrimp, and serve immediately.
Cook's Tip
Come colder weather, drain and rinse a can or two of cannellini beans, warm them up in a saucepan, and toss with some minced red onion, red pepper, pitted black olives, and a few leaves of basil or arugula. Pour a few spoonfuls of olive oil over the mixture and squeeze lemon juice over top. Season with salt and pepper, toss, and use as a bed for the shrimp.