Tomato Basil Risotto

Tomato Basil Risotto
Adapted from http://recipes.epicurean.com/recipe/11454/tomato-basil-risotto.html

8 c. vegetable broth
1/4 c. margarine, divided
1/4 c. chopped onion
1-1.5 c. chopped cherry tomatoes
1 c. mushrooms
2 c. Arborio rice
1/4 c. chopped fresh basil
1/4 tsp. salt
1/4 tsp. pepper

Cook broth in a saucepan over medium heat until hot. Melt 2 tbsp. butter in large pot over med-hi heat; add onion, and cook 2 minutes, stirring constantly. Add tomato; cook 2 minutes, stirring constantly. Add rice; cook 5 minutes. Reduce heat to medium. Add broth, 1/2 c. at a time, stirring constantly; allow rice to absorb liquid before adding more broth. Stir in remaining 2 tbsp. butter, chopped basil, and remaining ingredients.