1. Preheat oven to 400F. Combine peaches and juice of 1 lemon in a shallow gratin dish.
2. Place flour, sugar, and salt in the bowl of a food processor. Pulse until combined. Add cold butter. Pulse until mixture resembles coarse meal (about 5-6 pulses). Sprinkle mixture over peaches, pressing mixture together to create some larger chunks.
3. Bake 30-45 minutes or until peaches are bubbly and struesel is browned.