1. Prepare Crust: Place flour in bowl of a heavy-duty electric stand mixer; cut in cold butter with a pastry blender or fork until mixture resembles small peas. Chill 10 minutes.
2. Add bacon to flour mixture; beat at low speed just until combined. Gradually add sour cream, 1/4 cup at a time, beating just until blended after each addition.
3. Spoon mixture onto a heavily floured surface; sprinkle lightly with flour, and knead 3 or 4 times, adding more flour as needed. Roll to a 13-inch round. Gently place dough in a 9-inch fluted tart pan with 2-inch sides and a removable bottom. Press dough into pan; trim off excess dough along edges. Chill 30 minutes.
4. Meanwhile, prepare Filling: Cut 2 lb. tomatoes into 1/4-inch-thick slices, and remove seeds. Place tomatoes in a single layer on paper towels; sprinkle with 1 tsp. salt. Let stand 30 minutes.
5. Preheat oven to 425°. Stir together Cheddar cheese, next 10 ingredients, and remaining 1 tsp. salt in a large bowl until combined.
6. Pat tomato slices dry with a paper towel. Sprinkle cornmeal over bottom of crust. Lightly spread 1/2 cup cheese mixture onto crust; layer with half of tomato slices in slightly overlapping rows. Spread with 1/2 cup cheese mixture. Repeat layers, using remaining tomato slices and cheese mixture. Cut remaining 3/4 lb. tomatoes into 1/4-inch-thick slices, and arrange on top of pie.
7. Bake at 425° for 40 to 45 minutes, shielding edges with foil during last 20 minutes to prevent excessive browning. Let stand 1 to 2 hours before serving.