preheat oven 450

cook pasta

meanwhile, wisk flour & 2tbs milk in small bowl. heat remaining milk in large ovenproof skillet over med-high heat until steaming

gradually wisk a few tbs of hot milk in milk-flour mixture, then wisk mixture back in skillet. cook on med-high, stirring, until sauce is smooth & lightly thickened, about 1min. remove and stir in cheddar cheese, pepper Jack, chili powder, s&p.

purer cottage cheese until very smooth. stir into skillet. add tuna & pasta; stir well to coat with sauce. sprinkle drained tomatoes over top.

bake until hot & bubbling, 20-25mins