Melt butter in 4-quart saucepan over medium heat until sizzling. Add shallots, mushrooms and asparagus. Cook 4-5 minutes or until asparagus is crisply tender and shallots are softened. Remove vegetables from pan; set aside.
Place rice into pan; stir until well-coated. Cook 1 minute; add wine. Continue cooking, stirring occasionally, until wine is absorbed. Add stock 1/2 cup at a time, stirring occasionally after each addition, until liquid is absorbed.
Stir in cooked vegetables, cherry tomatoes, Parmesan cheese. Add lemon zest and salt, if desired.