Unroll dough, separating into strips. Working on a flat surface, coil one strip of dough around itself in a spiral pattern. Add second strip of dough to the end of the first strip, pinching ends together to seal; continue coiling dough. Repeat procedure with remaining dough strips. Cover dough with a towel; let rest 20 minutes. Roll dough into a 13-inch circle; fit into a 9-inch pie plate coated with cooking spray. Fold edges under; flute. Sprinkle cheese over bottom of crust; set aside.
Preheat oven to 375°.
Coat a large nonstick skillet with cooking spray; place over medium-high heat. Add ham, onion, salt, and pepper; cook 4 minutes. Arrange ham mixture over cheese.
Combine milk and egg substitute; stir well with a whisk. Pour over ham mixture. Bake at 375° for 45 minutes or until a knife inserted in center comes out clean; let stand 10 minutes. Garnish with cherry tomatoes, if desired.