Heat a large pan over med-low heat. Add 1-tablespoon olive oil. Sauté the pears for 2-3 minutes per side, until soft and brown around the edges. Set aside. Repeat with the plums.
Meanwhile, toast seeds in a dry skillet over med-low heat. Stir to prevent burning (about 3-5 minutes).
In a small bowl, whisk the olive oil, vinegar and garlic until emulsified. Season to taste with salt and pepper.
Toss arugula with the dressing. Top with the seeds and fruit. Season to taste.