Quantum Field Theory for Mathematicians: The approach to quantum field theory in this book is part way between building a mathematical model of the subject and presenting the mathematics that physicists actually use.

Or for a more basic introduction Peter Woit's lecture notes.

Quantum Field Theory for Mathematicians: The approach to quantum field theory in this book is part way between building a mathematical model of the subject and presenting the mathematics that physicists actually use.

For a collection of resources, see Peter Woit's lecture notes.