Preheat an oven to 450 degrees F (230 degrees C). Grease a baking sheet.
Spread onion and bell pepper in the prepared baking sheet and spray with cooking spray.
Bake in the preheated oven until golden, about 15 minutes.
Heat 1 tablespoon olive oil in a skillet over medium heat; cook and stir garlic and ginger in the hot oil until garlic begins to brown slightly, 2 to 3 minutes. Add pears to garlic mixture and cook until pears are evenly coated in oil, about 1 minute. Reduce heat to medium-low and pour 1 tablespoon ponzu over pears; cook until pears begin to brown, 5 to 10 minutes. Add more garlic and ginger if desired.
Mix remaining 3 tablespoons olive oil and 3 tablespoons ponzu in a small saucepan; bring to a boil. Add garlic and ginger if desired. Remove saucepan from heat and cool.
Combine greens, cucumber, onion, bell pepper, and pears in a bowl; drizzle with ponzu-olive oil mixture. Toss salad to evenly coat.