Splitting milk in tomatoes in bolognese

I'm planning on making a bolognese today.
The recipe calls for adding two cups of milk and a can of plum tomatoes.
It seems whenever I've attempted to make anything using milk and tomatoes the result is disgusting. The milk always splits.
I'm not going to go to the work/expense making this recipe until I know for sure it won't split on me.
What are the 100% fool-proof things not to do and to do to avoid this problem.
Thanks.