cook pasta in large pot of salted water as label directs. Drain and toss with the milk in large bowl, set aside.
mean while cook the bacon in large skillet over medium-high heat until crisp(turkey bacon is good for this.) drain dicard all but 3 tablespoons of drippings from pan. add tomatoes, thyme and garlic to pan and toss until warmed through: season with salt and pepper. crumble the bacon into bite-size pieces set aside 1/4 cut for garnish. Toss the remaining bacon and the tomato mixture with the pasta.
mix mayonnise, sour cream and 3 tablespoons chives with the pasta until evenly combined. Season with salt and pepper. Add lettuce; toss again to coat. Garnish with the remaining 1 tablespoon chives. Serve at room temperture.