Spray the bottom of the crock pot. Put frozen vegetables in the crock. Layer ½ the tater tots on the bottom of the pot. Sprinkle ½ of the bacon pieces on top of the tator tots. Combine the two cheeses and sprinkle ⅓ of it over the bacon,vegetables and tots. Top cheese with the chicken breasts.
Sprinkle chicken with salt and pepper to taste. Top chicken with another ⅓ of cheese. Sprinkle with other ½ of the bacon pieces. Add remainder of the tater tots. Top with final ⅓ of the cheese. Pour milk over the top. Set crock pot to high and cook 3-4 hours (3 was perfect for me).