Spread red peppers, zucchini, broccoli and peas on a cookie sheet and drizzle with olive oil. Toss to coat. Cook at 425 degrees Fahrenheit for 20 to 25 minutes, or just until the veggies are fork tender. Remove them from the oven every 5 minutes and toss so they'll roast evenly.

Cook pasta according to package directions. When it's almost done, with about 5 to 7 minutes left, start making the sauce. For the sauce, in a large skillet over the stovetop, melt butter over medium-low heat while stirring it around. Whisk in the flour, salt and pepper, then slowly whisk in the milk (1 c. at a time). Turn the heat up to medium-high and allow it to come to a low boil while stirring constantly. The sauce will bubble and thicken, then remove it from heat. Stir in grated cheddar, allowing it to melt fully. Drain pasta and stir sauce into it, along with the roasted veggies. Serve immediately.