Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 425 degrees. Wash and dry produce.

Trim and thinly slice scallions, separating whites from greens. Peel and mince or grate ginger. Dice sweet potato into ½-inch pieces. Trim and quarter mushrooms. Core, deseed, and dice bell pepper into ½-inch pieces.

Melt 1 TBSP butter (2 TBSP for 4 servings) in a small pot over medium-high heat. Add scallion whites and 1 TBSP ginger (2 TBSP for 4); cook, stirring, until fragrant, 1 minute.

Stir in rice, 1¼ cups water (2¼ cups for 4), and a pinch of salt. Bring to a boil, then cover and reduce to a low simmer. Cook until rice is tender, 15-18 minutes.

Keep covered off heat until ready to serve.

While rice cooks, in a medium bowl, toss sweet potato and mushrooms with a drizzle of oil, half the hoisin (you’ll use the rest later), salt, and pepper. Spread out on one side of a baking sheet.

Toss bell pepper on empty side with a drizzle of oil, salt, and pepper. (For 4 servings, use 2 sheets; roast sweet potato and mushrooms on top rack and bell pepper on middle rack.)

Roast on top rack until just tender, 15 minutes (veggies will finish cooking in step 5).

While veggies roast, in a small bowl, combine mayonnaise, sour cream, soy sauce, and as much Sriracha as you like. TIP: Start with half the Sriracha, then taste and add more from there if you like things spicy.

Once veggies have roasted 15 minutes, remove sheet from oven. (For 4 servings, remove sheet with sweet potato and mushrooms; leave bell pepper roasting.) Using a spatula, toss sweet potato and mushrooms with remaining hoisin and half the sesame seeds.

Return to oven until veggies are tender and glaze is tacky, 5-8 minutes more.

Fluff rice with a fork; season with salt.

Divide rice between bowls. Top with sweet potato and mushrooms, and bell pepper. Drizzle with as much Sriracha soy mayo as you like. Garnish with scallion greens and remaining sesame seeds. Serve.