Heat oil and butter in large saucepan over medium heat. Add onions; cook, stirring, until completely translucent. Add rice; cook over medium-high heat, stirring constantly, until rice begins to turn pale amber in color. Add ladlefuls of boiling chicken broth to rice, stirring, continually adding only the broth the rice will readily absorb, over a 20 - 25 minute period, plus a little more. After the first 10 minutes, add drained porcini mushrooms and reserved liquid (leave sediment behind). After the first 15 minutes, add bell peppers. When rice is al dente, stir in half-and-half and Parmesan cheese. Remove from heat, stir, and serve immediately. (Risotto consistency should be about like soft oatmeal mush.)