Adjust rack to top position (top and middle positions for 8 servings) and preheat oven to 425 degrees.

Heat a drizzle of oil in a small pot (medium pot for 8) over medium-high heat. Add tomato paste and cook, stirring, until darkened in color, 1-2 minutes.

Add rice, one of the stock concentrates (two for 8), 1¼ cups water (2¼ cups for 8), and a big 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 use in Step 4.

Meanwhile, wash and dry produce.

Halve bell peppers lengthwise; remove stems and seeds. Peel and mince or grate garlic.

Place bell peppers on a baking sheet (divide between two baking sheets for 8 servings) and drizzle each half with oil; rub to coat. Season with salt and pepper. Arrange cut sides down; roast on top rack (for 8, roast on top and middle racks, swapping rack positions halfway through) until tender, 10-15 minutes.

While peppers roast, finely dice tomato. Roughly chop cilantro. Trim and thinly slice scallions, separating whites from greens. Quarter limes.

In a small bowl, mix together tomato, scallion whites, half the cilantro, juice from 1 lime (for 8, use all the cilantro and juice from 2 limes), and a pinch of salt and pepper.

Heat a drizzle of oil in a large pan (for 8 servings, use two large pans or cook in batches) over medium-high heat. Add beef*, garlic, Mexican Spice Blend, remaining stock concentrates, salt, and pepper. Cook, breaking up meat into pieces, until browned and cooked through, 4-6 minutes.

Using a slotted spoon, transfer beef mixture to a large bowl.

Fluff rice with a fork (it’s OK if rice has a little extra liquid); transfer to bowl with beef mixture. Stir until thoroughly combined. Taste and season with salt and pepper if desired.

Once bell peppers are done roasting, remove sheet from oven. Carefully flip bell peppers and stuff each half with as much filling as will fit. Sprinkle with Mexican cheese blend.

Heat broiler to high or increase oven to 500 degrees.

Transfer stuffed peppers to top rack and broil or roast until cheese is melted and bubbly, 2-4 minutes (for 8 servings, broil or roast in batches). TIP: Watch carefully to avoid burning!

In a small bowl, combine guacamole and a squeeze of lime juice; season with salt and pepper to taste.

Divide stuffed peppers between plates. Top peppers with juice from two lime wedges (four wedges for 8 servings). (TIP: if you like things spicy, add a few dashes of hot sauce!) Garnish with scallion greens. Place guacamole, pico de gallo, and sour cream in separate serving bowls and serve with remaining lime wedges on the side.